Book of Abstracts
DSM 2016, Kyoto
BOOK OF ABSTRACTS
Sampling at the deepest bottom, Mariana Trench Challenger Deep (11,000 m)
5th International Workshop on Deep-Sea Microbiology
September 10-11, 2016, Kyoto, Japan
・This workshop is supported by The Kyoto University Foundation.
・This program is supported by a subsidy from Kyoto City and the Kyoto Convention & Visitors Bureau.
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5th International Workshop on Deep-Sea Microbiology
September 10-11, 2016, Kyoto, Japan
The aim of the workshop is to gather international experts in the field of deep-sea microbiology, and provide the participants the opportunity to present very recent data, and to discuss future cooperative works, in a friendly atmosphere. Oral presentations are basically made by selected scientists, but the meeting is open to a broad audience including PhD students and Post-docs. This will give young scientists the opportunity to listen to up to date talks, and meet and discuss with experts during the breaks. Just after this workshop, you can join the Extremophiles 2016 Kyoto congress (Sep. 12-16, http://www.acplan.jp/extremophiles2016/).
During the Extremophiles Conference held in Brest, France, in September 2006, the idea to hold a series of workshops dedicated to deep-sea microbiology was launched. Prof. Dr. Xiao Xiang (University of Shanghai, China) took the job and organized the first workshop in Xiamen, China, in November 2008, where he was settled at that time. The meeting was a great success and encouraged the organization of further workshops. The second WS was organized by Prof. Daniel Prieur (University of Brest, France) in September 2010 in Brest, France. The 3rd WS was organized again by Prof. Xiao Xiang, and held in Shanghai, China, in October 2012. The 4th WS was in Brest, France, in September 2014, and organized by Prof. Dr. Mohamed Jebbar (CNRS-Ifremer-UBO, France). The time has come to schedule the 5th WS in Kyoto, Japan, which will be held in September 2016.
Cooperated by The Japan Society for Bioscience, Biotechnology, and Agrochemistry (JSBBA) KANEKA Co. The Dreaming Company Syn Corporation Bioengineering Lab. Co. WDB Environmental & Biological Research Institute
Organizing Committee Local Committee: Satoshi Nakagawa (Chair, Kyoto University) Ken Takai (JAMSTEC) Chiaki Kato (JAMSTEC) Haruyuki Atomi (Kyoto University) Takuro Nunoura (JAMSTEC)
Scientific advisory board: Mohamed Jebbar (CNRS-Ifremer-UBO, France) Anne Godfroy (Ifremer, France) Douglas H. Bartlett (SIO, UCSD, USA) Anna-Louise Reysenbach (Portland University, USA) Xiang Xiao (SJTU, China) Ken Takai (JAMSTEC, Japan)
Office Laboratory of Marine Environmental Microbiology, Division of Applied Biosciences, Graduate School of Agriculture, Kyoto University, Oiwake-cho, Kitashirakawa, Kyoto 606-8502, Japan E-mail: [email protected] URL: http://www.kanbi.marine.kais.kyoto-u.ac.jp/Site/Workshop2016/Top.html
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General information About the Venue: Maskawa Hall, located in the North Campus, Kyoto University It’s 5-10 min walk from the venue of Extremophiles 2016 (September 12-16 @ Kyoto University Clock Tower Centennial Hall).
About Kyoto: Kyoto is often called "Japan's heartland". Over a period of 1200 years, dating from the decision to move the capital to Kyoto in 794, it nurtured a splendid, delicate and unique kind of culture, and over the course of history came to be considered the mother of culture within Japan. Natural scenery, temples, shrines, towns and homes intermingle with a poignant historical beauty. Whether it is the Tea Ceremony or Japanese flower arrangement or Nishijin-brocade, so many aspects of characteristic Japanese culture continue to thrive in Kyoto. For more information, see websites of travel+leisure and Kyoto city.
Kyoto Station
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Accommodation & Travel Hotels There are lots of hotels available in Kyoto. But, Kyoto is a very popular destination, so it is advised to book AS EARLY AS POSSIBLE (right now if you can). This is pretty important!!
Travel From airport
From Tokyo, (via Bullet train)
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From Kyoto station
Kyoto-city Guide Map See the following pdf → guidemap.pdf
Instruction for oral presentation You can use your own laptop computer. Please make sure that your PC has a VGA output. VGA connector is a three-row 15-pin DE-15 connector (Mini D-sub-15pin). Our computer (Mac OS10.8.5) is also available. PowerPoint (ver 2011) and Key Note (ver 5.3) are installed. All speakers are requested to preview their presentation files during a coffee or lunch break before the start of each session. Presenting allotted time is 20-30 min including discussion and change of speakers, speakers are kindly asked to keep the time of their presentations.
Instruction of poster presentation Poster size could be about A0 size (84 cm x 120 cm). The WS office will provide the pin and tapes for fix the poster on board. Poster presenters should set the poster on Sep. 10, morning, and take out on Sep. 11, evening.
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Scientific program Saturday, 10 September 2016 8:30 - Registration Desk Open 9:05 - 9:10 Opening address Workshop Chair: Satoshi Nakagawa (Kyoto Univ.)
Session 1. ・・・・・・9 Session Chair: Chiaki Kato (JAMSTEC) 9:10 - 9:50 O-1 Mohamed Jebbar (Univ. Brest, CNRS, Ifremer) Adaptation to high hydrostatic pressure in hyperthermophilic piezophiles from deep-sea hydrothermal vents. 9:50 -10:20 O-2 Anais Cario (Rensselaer Polytechnic Institute) Experimental high-pressure cultivation with the PUSH50: increased pressure tolerance of a marine bacterium without subsampling decompression. 10:20 - 10:50 Coffee break & Poster session
Session 2. ・・・・・・11 Session Chair: Mohamed Jebbar (Univ. Brest, CNRS, Ifremer) 10:50 - 11:20 O-3 André Antunes (Edge Hill University) Extreme biology in the deeps of the Red Sea. 11:20 - 11:40 O-4 Xiang ZENG (Third Institute of Oceanography, SOA) Ferric iron reduction by a piezophilic thermophilic fermentative bacterium Anoxybacter fermentans strain DY22613T from deep-sea hydrothermal vents. 11:40 – 12:10 O-5 Eva Sintes (University of Vienna) The role of sulfur sources for deep ocean microorganisms. 12:10 - 14:00 Lunch (not provided)
Session 3. ・・・・・・13 Session Chair: Takuro Nunoura (JAMSTEC) 14:00 - 14:40 O-6 Long-Fei Wu (CNRS-CAS) Occurrence and characteristics of magnetotactic bacteria in seamount habitats. 14:40 - 15:10 O-7 Weijia Zhang (Ins. Deep-Sea Sci. Eng., SOA) Contribution of TMAO to the high-hydrostatic pressure adaptation of deep-sea bacteria. 15:10 - 15:40 O-8 Masayoshi Nishiyama (Kyoto Univ.) Microscopic analysis of the swimming motility of deep-sea bacteria at high pressure. 15:40 - 16:10 O-9 Jun Kawamoto (Kyoto Univ.) Physiological function of polyunsaturated fatty acids in microbial cold and high-pressure adaptation. 16:10 - 16:40 Coffee break & Poster session
Session 4. ・・・・・・16 Session Chair: Long-Fei Wu (CNRS-CAS) 16:40 - 17:00 O-10 Chiaki Kato (JAMSTEC) Microbial diversity of the intestine from the deep-sea sharks and isolation of the Photobacterium sp. 17:00 - 17:20 O-11 Sotaro Fujii (Hiroshima Univ.) Comparative study on stabilization mechanism of monomeric cytochrome c5 from deep-sea piezophilic Shewanella violacea 17:20 - 17:50 O-12 Shunsuke Sato (Kaneka Co.) Environment compatible KANEKA biopolymer AONILEX®.
18:45 - 21:00 Dinner (Fortune garden; applicant only) →URL: http://www.fortunegarden.com/en/
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Sunday, 11 September 2016 Session 5. ・・・・・・18 Session Chair: Peter R. Girguis (Harvard Univ.) 9:00 - 9:30 O-13 So Fujiyoshi (Kyoto Univ.) Unique morphological features of deep-sea endemic crab ventral setae. 9:30 - 10:00 O-14 Yong Wang (Ins. Deep-Sea Sci. Eng., SOA) Genomic characterization of mycoplasma symbiotic bacteria from the stomach of deep-sea isopod Bathynomus sp. 10:00 -10:30 Coffee break & Poster session
Session 6. ・・・・・・19 Session Chair: Elizaveta Bonch-Osmolovskaya (Winogradsky Ins. Microbiol., RAS) 10:30 - 11:10 O-15 Peter R. Girguis (Harvard Univ.) Short, fat, skinny or tall: Rates and mechanisms of carbon fixation among siboglonid tubeworms at hydrothermal vents. 11:10 - 11:40 O-16 Masahiro Yamamoto (JAMSTEC) Electro-ecosystem in deep-sea hydrothermal fields. 11:40 - 12:00 O-17 Cécile Dalmasso (Univ. Brest, CNRS, Ifremer) Thermococcus piezophilus sp. nov., an hyperthermophilic archaeon with a broad pressure range for growth, isolated from the Mid-Cayman Rise. 12:00 - 14:00 Lunch (not provided)
Session 7. ・・・・・・21 Session Chair: Satoshi Nakagawa (Kyoto Univ.) 14:00 - 14:30 O-18 Brett J. Baker (Univ. Texas) Genomics uncovers the functional potential of microbial communities in deep-sea hydrothermal vent sediments. 14:30 - 15:00 O-19 Shingo Kato (JAMSTEC) Metabolic potential of uncultured bacteria in massive sulfide deposits below the deep seafloor revealed by metagenomic analyses. 15:00 - 15:30 O-20 Mercier Coraline (UBO) Discovery of bacteriophages amongst the order of Thermotogales. 15:30 - 16:00 O-21 Daniel De Corte (JAMSTEC, Univ. Vienna) Large-scale distribution of microbial and viral populations in the South Atlantic Ocean 16:00 - 16:30 Coffee break & Poster session
Session 8. ・・・・・・24 Session Chair: Ken Takai (JAMSTEC) 16:30 - 17:00 O-22 Tomoyo Okumura (JAMSTEC) Brucite-carbonate chimneys discovered in the Shinkai Seep Field, a serpentinite-hosted vent system in the Southern Mariana Forearc. 17:00 - 17:30 O-23 Sayaka Mino (Hokkaido Univ.) Population genetics and phenotypic differences of cosmopolitan mesophilic Sulfurimonas at deep-sea hydrothermal vents. 17:30 - 18:00 O-24 Elizaveta Bonch-Osmolovskaya (Winogradsky Ins. Microbiol., RAS) New catabolic processes that can fuel anaerobic deep-sea hydrothermal ecosystems.
18:00 - 18:05 Closing remarks Ken Takai (JAMSTEC)
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Poster ・・・・・・26
P-1 Xuegong Li (Ins. Deep-Sea Sci. Eng., SOA) Genomic analysis of an extremely piezophilic Shewanella benthica DB21MT-2 isolated from the Mariana Trench.
P-2 Qunjian Yin (Ins. Deep-Sea Sci. Eng., SOA) Effect of TMAO on piezophilic growth of marine bacteria.
P-3 Zhuo Li (Third Institute of Oceanography, SOA) The euarchaea DNA replication fork contains two copies of DNA polymerase D.
P-4 Takaaki Kuribayashi (Hiroshima Univ.) Difference in salt stability of membrane-bound 5’-nucleotidases purified from piezophilic, moderately-halophilic and piezosensitive, non-halophilic Shewanella species.
P-5 Lijing Jiang (Third Institute of Oceanography, SOA) Epibiosis insights associated with deep-sea hydrothermal vent shrimp Rimicaris exoculata revealed by metagenomics and metatranscriptomics.
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Saturday, 10 September 2016
Session 1.
O-1 Adaptation to high hydrostatic pressure in hyperthermophilic piezophiles from deep-sea hydrothermal vents.
Mohamed Jebbar1, Tiphaine Birien1, Grégoire Michoud1, Pauline Vannier1, Yann Moalic1, Axel Thiel1, Anais Cario2, Nicolas Martinez3, Mathieu Barba4, Vincent Daubin4, Bruno Franzetti3, Judith Peters3, and Phil Oger2 1Univ. Brest, CNRS, Ifremer, UMR 6197-Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), Institut Universitaire Européen de la Mer (IUEM), rue Dumont d’Urville, F-29280 Plouzané, France 2Univ. Lyon, ENS Lyon, CNRS UMR 5276, F -69364 Lyon cedex 07, France 3Univ. Grenoble Alpes, IBS, Institut Laue Langevin, F-38042 Grenoble Cedex 9, France 4Univ. Lyon, CNRS, INRIA UMR 5558, F-69622 Villeurbanne Cedex, France
The deep biosphere (continental underground and in oceans below 1000 m in depth) could represent up to 70% of all cells on Earth, as well as 50% of the primary production of biomass. The deep sea is characterized not only by high pressures (up to 110 MPa) but also by a lack of sunlight, an extremely low temperature (<5°C) except in the vicinity of hydrothermal vents, where temperature may be as high as 460°C, but water remains liquid owing to the high hydrostatic pressure (HHP) (1). HHP has numerous effects on organisms and cellular components, resembling that of an increase or a decrease in temperature, such as protein denaturation, membrane destabilization, alteration of transcription and translation (1). HHP is however required for optimal activity of deep biosphere adapted microbes (piezophiles) (1). Since the discovery of deep-sea hydrothermal vents, many mesophilic and hyper/thermophilic Bacteria and Archaea have been described but only a few thermo-piezophilic belonging mainly to the Thermococcales group have been described so far. In thermophilic piezophiles it is evidenced that the adaptation to HHP involves a global change in the expression of genes of some metabolic pathways, rather than the expression of a stress response per se (2). Differential proteomics and transcriptomics analyses identified key hydrostatic pressure-responsive genes involved in translation, chemotaxis, energy metabolism (hydrogenases and formate metabolism) and Clustered Regularly Interspaced Short Palindromic Repeats sequences associated with Cellular apoptosis susceptibility proteins.(3). However, a stress response is observed in the piezosensitive thermophilic species (2). Using the neutron scattering techniques, we are currently investigating the protein structure of Thermococcus barophilus to further characterize HHP adaptation at the molecular level (4). We have shown that the adaptation to HHP involves osmolytes accumulation to maintain proper protein folding and activity (5). We have direct and indirect evidence for the structural adaptation of the proteome, although the specific signature at the genome level still remains elusive. The study of activities and structures of glyoxilate hydroxypyruvate reductase (GRHPR) enzymes from 3 Thermococcales species displaying different piezophilic properties suggested that sub-optimal temperatures represent important conditions to assess for high-pressure adaptation in deep-sea thermophilic enzymes. Finally, genetic manipulations were performed in T. barophilus (6) in order to investigate the functions of some above pathways in vivo and to examine the roles of related enzymes. This will provide greater insight into the piezophilic lifestyle of thermo-piezophiles microorganisms dwelling in deep biosphere.
References 1- Jebbar M, Franzetti B, Girard E, and Oger P. 2015. Microbial diversity and adaptation to high hydrostatic pressure in deep-sea hydrothermal vents prokaryotes. Extremophiles. 19(4): 721-740 2- Vannier P, Michoud G, Oger P, Marteinsson VT, Jebbar M. 2015. Genome expression of Thermococcus barophilus and Thermococcus kodakarensis in response to different hydrostatic pressure conditions. Res Microbiol. 166(9): 717-725 3- Michoud G, Jebbar M. 2016. High hydrostatic pressure adaptive strategies in an obligate piezophile Pyrococcus yayanosii. Sci Rep. Jun 2;6:27289. doi: 10.1038/srep27289 4- Peters J, Martinez N, Michoud G, Cario A, Franzetti B, Oger P, and Jebbar M. 2014. Deep Sea Microbes Probed by Incoherent Neutron Scattering Under High Hydrostatic Pressure. Z. Phys. Chem. 228 (10-12), 1121-1133.
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5- Cario A, Mizgier A, Thiel A, Jebbar M, and Oger P. 2015. Restoration of the di-myo-inositol-phosphate pathway in the piezo-hyperthermophilic archaeon Thermococcus barophilus. Biochimie. 118: 286-293 6- Thiel A, Michoud G, Moalic Y, Flament D and Jebbar M. 2014. Genetic manipulations of the hyperthermophilic piezophilic archaeon Thermococcus barophilus. Appl Environ Microbiol. 80(7): 2299-2306
O-2 Experimental high-pressure cultivation with the PUSH50: Increased pressure tolerance of a marine bacterium without subsampling decompression.
Karyn L. Rogers1, Anaïs Cario1, Hervé Cardon2, Isabelle Daniel2 1 Department of Earth and Environmental Sciences, RPI, Troy, NY12180, USA 2 Laboratoire de Géologie de Lyon, UMR 5276 CNRS, ENS & Université de Lyon, France
The deep biosphere is one of the largest ecosystems, and yet one of the least explored microbial habitats on the planet. The most common sampling and cultivation techniques require decompression during sample handling, which can lead to biases in both the diversity and physiology of isolates retrieved from those environments. The recent development of the Pressurized Underwater Sample Handler System (PUSH50), a part of the Deep Carbon Observatory’s PRIME (Piezophile Research Instrumentation for Microbial Exploration) Facility, overcomes this decompression requirement and allows for both sample retrieval and cultivation without decompression. In this study we used the PUSH50, a variable-volume, floating-piston reactor to grow the marine bacterium Desulfovibrio salexigens under a range of elevated pressure conditions (from 0.1 MPa to 50 MPa). These experiments were compared with the traditional high-pressure cultivation that involves decompression for each subsampling event. The effect of both elevated growth pressures, as well as experimental decompression, was evaluated by measuring the cell density and the survival ratio for each pressure condition. The strain was much more sensitive to elevated pressure when cultivated and subsampled with decompression than when subsampling did not require decompression. Both the growth rate and the survival ratio were improved when D. salexigens was cultivated at high pressure without subsample decompression. Our study demonstrates that high-pressure growth of a piezosensitive strain is enhanced when subsampling decompression is avoided. These results emphasize the need to maintain a constant experimental pressure during cultivation of piezosensitive strains. It also highlights the importance of sampling and cultivating deep-sea samples under in situ conditions in order to avoid biases associated with sample decompression. The PUSH50 will be available to the broader scientific community for deep biosphere research and therefore will enhance the high-pressure microbiology field by significantly improving our understanding of deep-sea microorganisms in global elemental cycles.
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Session 2. O-3 Extreme biology in the deeps of the Red Sea.
André Antunes Biology Department, Edge Hill University, Ormskirk, UK.
The Red Sea harbours multiple deep-sea anoxic brine pools along its central axis. They are considered to be some of the harshest environments known on our planet due to the conjugation of high salinity, increased temperature, high concentration of heavy metals, high pressure and anoxia. Each brine pool provides a unique combination of physical-chemical conditions, and this variety of ecological niches is further enhanced by the formation of steep gradients along the brine-seawater interface. Such unique settings make them a privileged location for novel discoveries in the field of microbiology. Although originally thought to be sterile, the brines have been shown to be teeming with life. There has been a recent significant increase in the number of scientific expeditions and studies looking into their biology, using a wide range of novel molecular-based approached (e.g. whole-genome sequencing, metagenomics, single-cell genomics). These studies resulted in important insights into the microbial community structure and its variability, the identification of several new phylogenetic groups and unusual novel extremophiles, and even the first macrofauna associated with the brine-seawater interface. In addition to their proven source of biological novelty, other studies have demonstrated their biotechnological potential (as producers of interesting enzymes or cytotoxic and apoptotic molecules). This presentation will provide an overview of the latest findings, current challenges, and future perspectives when studying the biology of these unusual extreme environments. Despite the recent increase in research, most of the brine-pools still remain unstudied and unsampled so further discoveries can be expected.
O-4 Ferric iron reduction by a piezophilic thermophilic fermentative bacterium Anoxybacter fermentans strain DY22613T from deep-sea hydrothermal vents.
Xiang ZENG1, Xi LI1, Zongze SHAO1*. 1Key Laboratory of Marine Biogenetic Resources, the Third Institute of Oceanography SOA, Xiamen, Fujian 361005, PR China
A novel piezophilic thermophilic anaerobic fermentative bacterial strain, designated strain DY22613T, was isolated from a deep-sea hydrothermal sulfide deposit at the East Pacific Rise (102.6° W, 3.1°S). Strain DY22613T is capable of reducing Fe(Ⅲ) compounds, including Fe(Ⅲ) oxyhydroxide (pH 7.0), amorphous iron(Ⅲ) oxide (pH 9.0), goethite (α-FeOOH, pH 12.0), Fe(Ⅲ) citrate, and elementary sulfur. The growth is sustained by fermentation rather than Fe(Ⅲ) respiration. Whereas in the presence of Fe(Ⅲ), the amount of final product (acetate, butyrate, CO2) and biomass become higher, which means that the oxidation of organic matter is greater than fermentation alone. Strain DY22613Tdiverts electron flux to hydrogen production and iron reduction. Besides, the bacterium produces well-formed single-domain magnetite in presence of Fe(Ⅲ) oxyhydroxide and iron-sulfur complex in presence of Fe(Ⅲ) citrate. The genome size of this strain is about 3.56 Mb. The extracellular reductase or electron shuttles are responsible for the transfer of electrons to the soluble carrier, which is different from c-type cytochromes mechanism.
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O-5 The role of sulfur sources for deep ocean microorganisms.
Eva Sintes1, Daniele De Corte1,2, Chie Amano-Sato1, Gerhard J. Herndl1. 1Dep Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria. 2Marine Functional Biology Group, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
Oceanic prokaryotes play a key role in the global elements cycles. In the pelagic realm, the microbial sulfur cycle has been largely studied in oxygen minimum zones and in the plume waters of hydrothermal vents. However, little is known about the sulfur sources for microbes inhabiting the oxygenated dark ocean water column representing the vast majority of the ocean’s volume. The active community from North Atlantic deep waters was characterized based on their capacity to incorporate the thymidine analogs bromodeoxyuridine (BrdU) in combination with next generation sequencing, or 5-ethynyl-2´-deoxyuridine (EdU) in combination with click chemistry. Additionally, selected samples from the mesopelagic (500 m) and bathypelagic (down to 2750 m) realm of the North Atlantic were amended with thiosulfate or thiosulfate plus a mix of organic compounds to elucidate the effect of sulfur sources on the microbial community composition. The addition of the substrates triggered a fast change of the active community. Chemoautotrophic organisms, such as SAR324, Nitrospina and SUP05, were only stimulated in discrete bathypelagic samples. However, heterotrophic microbes, such as Alteromonas and Vibrio, able to oxidize sulfur as additional energy source, were largely stimulated in the mixed amendments. Taken together, our results indicate a significant role of sulfur sources in the metabolism of deep ocean microbes.
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Session 3. O-6 Occurrence and characteristics of magnetotactic bacteria in seamount habitats.
Long-Fei WU LIA-BioMNSL, CNRS-CAS, LCB, Marseille, France
Magnetotactic bacteria (MTB) are a morphologically, phylogenetically and physiologically heterogeneous group of prokaryotes that produce single domain (SD) magnetite (Fe3O4) or greigite (Fe3S4) crystals within intracellular membrane organelles termed magnetosomes. The magnetosomes confer on cells a magnetic dipole moment that allows them aligning and swimming along the geomagnetic field lines to localize at the oxic-anoxic interface in the chemically stratified sediments of freshwater or marine environments. Although they ubiquitously occur in coastal marine sediments, magnetotactic bacteria have been observed only in limited deep-sea habitats mainly due to technical difficulty to access to this particular environments. The questions is how deeply and widely occurring the magnetotactic bacteria in deep-sea environment. Seamounts represent a peculiar oceanic ecosystem. They rise from the ocean seafloor and remain below sea level. Such topographic feature disturbs underwater currents and creates upwelling water flow, which often attracts plankton, corals, fish, and marine mammals alike forming biological hotspots in Oceans. It has been hypothesized that seamounts harbor high levels of biodiversity and endemism. We are particular interested in occurrence of magnetotactic bacteria on seamounts and in detection of novel species dwelling only on seamounts. At present MTB has been observed only at one sampling site located on a seamount on the eastern slope of the Walvis Ridge at a water depth of 1007 m. We performed the first systematic search of magnetotactic bacteria on a seamount. Magnetotactic bacteria were observed at all 14 stations on the four slopes of the Mariana seamount ranging from 238 to 2000 m below water surface. In addition, we have observed a flagellar apparatus with unprecedented rich of flagella arranged in highly organized array. This finding extends the occurrence of magnetotactic bacteria to the seamount ecosystems and suggests a motility adaptation to this kind of habitat.
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O-7 Contribution of TMAO to the high-hydrostatic pressure adaptation of deep-sea bacteria.
Wei-Jia ZHANG1,3, Qun-Jian YIN1,3, Sheng-Da ZHANG1,3, Ting Jiang1,3 and Long-Fei WU2,3 1Deep-sea microbial cell biology, Department of Deep Sea Sciences, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China. 2LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. 3France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/IDSSE-CAS, Sanya, China.
Trimethylamine N-oxide (TMAO) is one of the most extensively studied osmolytes and protein stabilizers. It is commonly found in the marine environment and abundant in the muscle tissues and plasma of marine fish and invertebrates. TMAO functions as a protein-folding stabilizer while counteracting destabilizers like urea and low temperature. In addition, several in vitro studies demonstrated that TMAO protects protein complex (e.g. F0F1-ATPase and MscK bacterial mechanosensitive channels) from the inactivation effect by high hydrostatic pressure (HHP). It is recently observed that the accumulation of TMAO in fish tissues is proportional with depth, indicating an important role in the high-pressure adaptation of deep-sea fishes. TMAO also serves as an electron acceptor in bacteria for generating energy via anaerobic respiration. Previous transcriptome and proteome studies showed that the expression of TMAO reductase is elevated under HHP in several deep-sea bacteria. In order to understand whether the TMAO anaerobic respiration involves in the high-pressure adaption of deep-sea bacteria, we analyzed the influence of TMAO on cellular growth of two deep-sea strains, and on the expression and activity of TMAO reductase under different pressure conditions. The growth of moderate piezophilic strain Photobacterium phospherum ANT-2200 under HHP is slightly augmented by TMAO. Four gene clusters encoding TMAO reductases are identified in the genome, and they are differently regulated by pressure and TMAO. Elevated hydrostatic pressure enhances the TMAO reductase activity, mainly due to the increase of isoenzyme TorA1. The QY27 strain isolated at the depth of 2500 m belongs to the genera of Vibrio. Interestingly, the growth under ambient pressure is slightly increased by the addition of TMAO, but significantly promoted under pressure up to 30 MPa, and it turns from piezo-sensitive into piezophilic. However, unlike strain ANT-2200, the expression and the activity of TMAO reductases of QY27 are regulated by TMAO only, but not by the changing of pressure. Taken together, our results imply the pressure tolerance is co-related with the physiological status of deep-sea bacteria, and different strategies are developed by bacteria to adapt to deep-sea habitats where the TMAO availability increases with depth.
O-8 Microscopic analysis of the swimming motility of deep-sea bacteria at high pressure.
Masayoshi Nishiyama1, Chiaki Kato2, Hiroshi Imai3, Shinji Kamimura3 and Yoshie Harada4 1Kyoto Univ., Kyoto, Japan. 2JAMSTEC, Japan. 3Chuo Univ., Tokyo, Japan. 4Osaka Univ., Osaka, Japan.
We have developed a high-pressure microscope that enables us to acquire high-resolution microscopic images, regardless of pressures. The high-pressure devices could be used up to 150 MPa, which is ~1.5-fold higher than in the deepest part of Mariana Trench (~11,000 m in depth), the highest found outside the crust of the earth. The developed system allowed us to characterize the pressure-induced changes in the motility of swimming E. coli cells and single flagella motors [1,2]. Our results showed that the motility of swimming cells and motors decreased with increased pressures. Here, we characterized the pressure dependence of the swimming motility of an absolutely piezophilic bacterium, Shewanella benthica strain DB21MT-2. This strain was isolated from the world’s deepest sediment (Mariana Trench, Challenger Deep at a depth of ~11,000 m). The cells were cultivated in pressure vessel at 80 MPa. The cultivated medium was enclosed in the high-pressure chamber, and then monitored the cells at various pressure conditions. Most cells did not swim in solution at 0.1 MPa. In contrast, the fraction of the swimming cells increased with increases of pressures, and then reached to a maximum at 50 MPa. The fraction and speed of the swimming cells
14 DSM 2016, Kyoto were ~0.2 and ~15 µm/s, respectively. Our results showed that DB21MT-2 is equipped with motility machinery suitable for high hydrostatic pressure environments.
References: [1] Nishiyama & Sowa. Biophys J. 102: 1872-1880 (2012). [2] Nishiyama et al., J. Bacteriol. 195: 1809-1814 (2013).
O-9 Physiological function of polyunsaturated fatty acids in microbial cold and high-pressure adaptation.
Jun Kawamoto and Tastuo Kurihara Institute for Chemical Research, Kyoto University, Uji, Kyoto, Japan.
Polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), bioactive compounds found from various organisms from bacteria to human and have been attractive a great deal of attention over the last decade. PUFAs are present as an acyl chain of membrane phospholipids and supposed to modulate functions of various membrane proteins by changing the physicochemical properties of the membrane. Biosynthesis of PUFAs is known to be a common feature of microbial cold and high-pressure adaptation, and a gene cluster for EPA or DHA biosynthesis are found from various isolates from Polar Regions and deep sea environments, suggesting that PUFAs-containing phospholipids play important roles in the adaptation to their habitats. On the other hand, the molecular mechanism and behavior of PUFAs in the physiological membrane are still uncleared. A piezophilic Gram-negative bacterium, Shewanella violacea DSS12, was isolated from a depth of 5,110 m and shows optimum growth at 30 MPa. A gene-disrupted mutant of one of EPA-biosynthesis genes showed the growth retardation at 30 MPa, but not at 0.1 MPa. At 30 MPa, this mutant formed filamentous cells, in which a number of Z-rings and separated nucleoids were observed. These defects of the growth and cell division were suppressed by exogenous supplementation of EPA-containing phospholipids, suggesting that EPA-containing phospholipids function at the later step of Z-ring formation of S. violacea DSS12 under high-pressure conditions. As a model strain for PUFAs research, we used a related strain, S. livingstonensis Ac10, which was isolated from Antarctic seawater and inducibly produces EPA-containing phospholipids at 4 ˚C. We synthesized an NBD-labeled phospholipid containing eicosapentaenyl group to visualize the membrane localization of EPA-containing phospholipids. Visualization analysis by using this synthetic probe demonstrated the presence of a membrane domain composed of EPA-containing phospholipids at the cell division site, in which EPA-containing phospholipids might support the function of proteins involved in the cell division at low temperatures.
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Session 4. O-10 Microbial diversity of the intestine from the deep-sea sharks and isolation of the Photobacterium sp.
Chiaki Kato1, Ayaka Sakai1, Mayu Yoshinari2, Masaru Kawato1, Shinji Tsuchida1 and Yoshihiro Fujiwara1. 1Dept. Marine Biodiversity, JAMSTEC, Yokosuka, Japan. 2School of Marine Biodiversity, Kitasato University, Sagamihara, Japan.
To understand the top predator of the deep-sea, we have started the new project to study about the predation of the possible candidate, the deep-sea sharks. As part of the project, we have performed to analyze the microbial diversity of the intestine from the deep-sea sharks to get some information of their dietary habitat. [METHOD] Several deep-sea sharks called, Sagami-sharks (Deania hystricosa) , Yoroi-sharks (Dalatias licha) and Yume-sharks (Centroscymnus owstonii), were obtained from Suruga Bay at depth of 200~500m by collaboration with the fisherman's ship, "Chouken-Maru", operated by Chaptain Hasegawa at Yaizu harbor. The intestine of the sharks were cut out in the harbor and about 1 g of the intestine samples, respectively, were used for further microbial studies. [RESULT] Profiles of the microbial diversity by the terminal restriction fragment morphology and next generation sequencing procedure from the Sagami- and Yoroi-sharks' intestines were very similar, so, Bacillus, Staphylococcus, Actinomycetes, Streptococcus, Escherichia, and Photobacterium were mainly detected. But, the profiles of the microbial diversity from Yume-sharks were very simple, so mostly Photobacterium was detected more than 90%. From the stable isotope analyses by another part of the project, Yume-shark could be most possible candidate of the top predator during those shark species, so it might be very interesting such differences of the microbial diversity. To analyze the function of the intestine Photobacterium sp., we have succeeded to isolate this species, and identified that the isolate could be mesophilic piezophiles growth properties. Further analyses are now in progress.
O-11 Comparative study on stabilization mechanism of monomeric cytochrome c5 from deep-sea piezophilic Shewanella violacea.
Sotaro Fujii1, Misa Masanari1, and Yoshihiro Sambongi1 1Graduate School of Biosphere Science, Hiroshima University, Hiroshima, Japan.
Shewanella species are gamma-proteobacteria widely distributed from deep-sea to shallow-water areas. A phylogenetic tree based on the Shewanella 16S rRNA gene sequences indicates that the species can be classified into two groups. Group 1 are mostly isolated from deep-sea environments, and Group 2 ones from shallow-water, growing piezophilically and piezo-sensitively, respectively. Although the two groups greatly differ in growth pressures, the Shewanella species in both groups have highly homologous proteins, thus comparative protein stability studies can be carried out. Cytochrome c5 from S. violacea (SVcytc5) in Group 1 exhibited high stability compared with the homologous cytochrome c5 from S. livingstonensis (SLcytc5) in Group 2, indicating that the pressure adaptation of these Shewanella species reflects the difference in stability between SVcytc5 and SLcytc5. In this study, we first determined the crystal structure of SVcytc5, which revealed potential amino acid residues responsible for the higher stability than that of SLcytc5. The SVcytc5 structure at 0.1 MPa revealed that the Lys-50 residue on the flexible loop formed a hydrogen bond with heme whereas the corresponding hydrophobic Leu-50 in SLcytc5 could not form such a bond, which appeared to be one of possible factors responsible for the difference in stability between the two proteins. This structural insight was confirmed by a reciprocal mutagenesis study on the thermal stability of these two proteins. As SVc5 was isolated from a deep-sea piezophilic bacterium, the present comparative study indicates that adaptation of SVc5 to high-pressure environments results in protein-folding stabilization against heat.
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O-12 Environment compatible KANEKA biopolymer AONILEX®.
Shunsuke Sato1, Kenichiro Nishiza2, and Tetsuo Okura1 1Corporate R&D Planning and Administration Division, GP group, Kaneka Corporation, 1-8 Miyamae-Cho, Takasago-Cho, Takasago, Hyogo 676-8688, Japan. ([email protected]) 2Kaneka Belgium N.V. Green polymer Division, Nijverheidsstraat 16, 2260 Westerlo, Oevel, Belgium ([email protected]).
We have been developing biodegradable and bio-based polymer “AONILEX®” as an environment compatible material. AONILEX® consists of (R)-3-hydroxybutyrate and (R)-3-hydroxyhexanoate. This polymer is 100% made from renewable material such as plant oil by bacteria. [1,2]. The most important features are excellent biodegradability and non-toxicity. Various microorganisms which live in soil, river, and marine can take in and digest AONILEX® as a carbon and an energy source. Also the biodegradation happens under both aerobic and anaerobic conditions [3]. Therefore, AONILEX® is very good to use in agriculture applications, compostable applications and marine degradable applications. In addition, AONILEX® was considered to have no acute toxicity to sea lives, such as zooplankton, fish, and bivalve. It is verified recently that marine habitants are spoiled by man-maid plastic debris with consequence of ingestions and entanglement. Examination of encounters according to species highlighted that all known species of sea turtle and more than half of all known species of marine mammal and sea bird have ingested or become entangled in marine debris [4]. In the marine environment, plastic is fragmented into smaller pieces, mainly by UV radiation. These fragments absorb and concentrate hydrophobic compounds from sea water [5]. It is greatly concerned that these compounds would be transport from an invertebrate to mammals by a food chain. We believe that AONILEX® could be a solution of current marine pollution and could also contribute the protection of sea life in the long term.
[1] Sato S., et al. J Biosci Bioeng. 116(6), 677-681 (2013). [2] Sato S., et al. J Biosci Bioeng. 120(3), 241-251 (2015). [3] Kasuya K., et al. Int. J Biological Macromolecules. 19, 35-40 (1996). [4] Gall S.C., et al. Marine Pollution Bulletin. 92, 170-179 (2015). [5] Tanaka, T., et al. Environ Sci Technol. 49(19), 11799-11807 (2015)..
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Sunday, 11 September 2016
Session 5. O-13 Unique morphological features of deep-sea endemic crab ventral setae.
So Fujiyoshi1, Tomo-o Watsuji2, Shigeki Sawayama1 and Satoshi Nakagawa1,2 1Graduate School of Agriculture, Kyoto University, Kyoto, Japan. 2JAMSTEC, Kanagawa, Japan.
In deep-sea hydrothermal fields, a variety of invertebrates (tubeworms, mollusks, shrimps and crabs) forms symbiotic relationships with specific bacteria, although little is known about how the symbionts are selectively acquired and kept by the host invertebrate. We found that the serum components of the deep-sea endemic crab, Shinkaia crosnieri, selectively bound to some episymbiotic bacteria on the host setae in the previous study. The results suggest that the serum may play a role in the crab-symbiont interaction. The present study has focused on morphological properties of the setae in three species of decapod crustaceans; deep-sea endemic crab, marine non-symbiotic squat crab, and fresh water non-symbiotic hairy mitten crab, to understand why the epibiotic bacteria adhere to the host. In addition, water fluid simulation and observation of the adhesive setae to fine silica particles using light microscopy were performed. These experiments demonstrated that i) the setule (a spine on a seta) length of the deep-sea endemic crab was constant despite its body size, and it was significantly shorter than that of other two species, ii) the shorter setules allowed water intrusion to setae more frequently than in other two cases, and iii) more silica particles attached to the setae of deep-sea endemic crab than those of other two species. These results are new findings of the correlation between setae morphology and specific adhesion of silica particles. We will discuss possible functions of the setae in the host-symbiont interactions.
O-14 Genomic characterization of mycoplasma symbiotic bacteria from the stomach of deep-sea isopod Bathynomus sp.
Yong Wang1, Jiao-MeiHuang1, Antoine Danchin2, and Li-Sheng He1 1Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, Hainan, China. 2Institute of Cardiometabolism and Nutrition, Hôpital de la Pitié-Salpêtrière, 47 boulevard de l'Hôpital, 75013 Paris, France.
Deep-sea isopod scavengers such as Bathynomus sp. are able to live in nutrient-poor environments, which is likely attributable to the presence of symbiotic microbes in their stomach. In this study we recovered two draft genomes of mycoplasmas, Bg1 and Bg2, from the metagenomes of the stomach contents and stomach sac of a Bathynomus sp. sample from the South China Sea (depth of 898 m). Phylogenetic trees revealed a considerable genetic distance to other mycoplasma species for Bg1 and Bg2. Compared with terrestrial symbiotic mycoplasmas, the Bg1 and Bg2 genomes were enriched with genes encoding phosphoenolpyruvate-dependent phosphotransferase systems (PTSs) and sodium-driven symporters responsible for the uptake of sugars, amino acids and other carbohydrates. The genome of mycoplasma Bg1 contained sialic acid lyase and transporter genes, potentially enabling the bacteria to attach to the stomach sac and obtain organic carbons from various cell walls. Both of the mycoplasma genomes contained multiple copies of genes related to proteolysis and oligosaccharide degradation, which may help the host survive in low-nutrient conditions. The discovery of the different types of mycoplasma bacteria in the stomach of this deep-sea isopod affords insights into symbiotic model of deep-sea animals and genomic plasticity of mycoplasma bacteria.
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Session 6. O-15 Short, fat, skinny or tall: Rates and mechanisms of carbon fixation among siboglonid tubeworms at hydrothermal vents.
Peter R. Girguis1, Jessica Panzarino1, Tom Yu1, Jenny Delaney1, and Roxanne Beinart1,2 1Dept of Organismic and Evolutionary Biology, Harvard University, Cambridge, USA. 2Graduate School of Oceanography, University of Rhode Island, Narragansett, USA
The siboglonid tubeworms Riftia pachyptila and Ridgeia piscesae are among the best-studied hydrothermal vent symbioses. These worms have no mouth, gut or anus and are among the fastest growing organisms on Earth. Many studies have looked at aspects of primary productivity, including assessments of carbon fixation pathways, stable carbon isotope ratios, and net carbon fixation rates. In recent years, metagenomic, metaproteomic and enzymatic studies have suggested that Riftia and Ridgeia possess two different carbon fixation pathways: the Calvin-Benson-Bassham (CBB) and the reductive Tricarboxylic Acid (rTCA) cycles. Very few organisms are known to possess and use two different carbon fixation pathways. To date, it remains unclear if and when Riftia or Ridgeia are using both pathways to fix carbon, and accordingly we have conducted a series of experiments on Ridgeia piscesae to better understand A) if both modes of carbon fixation are active in these worms; B) if they are more active at different environmental conditions; and C) if differences in activity could serve to explain the range of stable carbon isotope ratios seen among Ridgeia morphotypes. We collected and incubated ~40 worms in our high-pressure aquaria, and conducted a series of mass spectrometric, metagenomic and metaproteomic analyses. The results strongly suggest that there is differential expression of the rTCA and CBB pathways among the various morphotypes and, surprisingly, that the differences in protein expression are consistent with changes in the geochemical regime at which the different morphotypes are found. Moreover, the different modes of carbon fixation influenced the rates of nitrate and ammonia assimilation, with the onset of rTCA leading to a massive increase in nitrate uptake. All together, these data suggest that Ridgeia tubeworm symbionts may have co-opted one of these carbon fixation pathways in response to the differences in physiological demand (and thus selective pressures) across the range of geochemical conditions in which the worms thrive.
O-16 Electro-ecosystem in deep-sea hydrothermal fields.
Masahiro Yamamoto1,2, Ryuhei Nakamura3, Takafumi Kasaya2, Mariko Abe1, Akiko Tanizaki1, Miwako Tsuda2, Satoshi Kawaichi3, Yoshihiro Takaki1,2, Hidenori Kumagai2, Katsuhiko Suzuki2 and Ken Takai1,2 1Department of Subsurface Geobiological Analysis and Research, JAMSTEC, Yokosuka, Japan. 2Project Team for Development of New-generation Research Protocol for Submarine Resources, JAMSTEC, Yokosuka, Japan. 3Center for Sustainable Resource Science, RIKEN, Wako, Japan.
We have proposed that deep-sea hydrothermal vent is a natural fuel cell with some experimental results, those are i) sulfide minerals forming vent wall is good electric conductor, ii) surfaces of the sulfide minerals effectively catalyze redox reactions such as oxidation of hydrogen sulfide, iii) there are redox potential gap between hydrothermal fluid and ambient seawater, and iv) electricity generates between two electrode inserted into hydrothermal fluid and seawater, respectively. The spontaneous electricity generation from deep-sea hydrothermal vent must strongly influence to transfer of ambient energy and materials, formation and dissolution of minerals, and structure of microbial community. In this presentation, we introduce our recent trial to prove the electricity generation and electro-ecosystem around deep-sea hydrothermal vents. We measured redox potentials on surfaces of sediment-free seafloor around deep-sea hydrothermal vents with an in-situ electrochemical analyzing system equipped on ROV. The nearer ROV moved to hydrothermal vents, the lower values of the redox potentials were. We also confirmed that the low potentials were not attributed by the composition of
19 DSM 2016, Kyoto the rock type of basement but by hydrothermal fluid behind the rocks. Spontaneous electricity generation was proved, because the negative potential on the surface of minerals could reduce oxygen gas in seawater. Next, we tried in-situ electrochemical cultivation on deep-sea hydrothermal vent. Component of microbial community was changed by electricity during 12 days. We are expecting that it is an electro-ecosystem. Now, we are trying isolation of electron-eating microorganisms from sulfide minerals collected from deep-sea hydrothermal vents. Our results are indicating that deep-sea hydrothermal field is an ideal experimental field for unknown natural electro-ecosystem.
O-17 Thermococcus piezophilus sp. nov., an hyperthermophilic archaeon with a broad pressure range for growth, isolated from the Mid-Cayman Rise.
Cécile Dalmasso1, Philippe Oger2, Gwendoline Selva1, Damien Courtine1, Stéphane L’Haridon1, Alexandre Garlaschelli1, Erwan Roussel1, Junichi Miyazaki3, Julie Reveillaud1, Mohamed Jebbar1, Ken Takai3, Lois Maignien1, Karine Alain1 1Laboratoire de Microbiologie des Environnements Extrêmes (LM2E), UMR 6197 UBO-CNRS-Ifremer, Plouzané, France 2Université de Lyon, INSA Lyon, CNRS UMR 5240, Villeurbanne, France 3Department of Subsurface Geobiological Analysis and Research (D-SUGAR), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan
A novel strictly anaerobic, hyperthermophilic archaeon, designated strain CDGST, was isolated from the deepest known deep-sea hydrothermal vent (the Beebe vent field, so-called Piccard), in the Cayman Trough, at 4964 m water depth. Its physiology and its genome were analyzed [1, 2]. The novel isolate belongs to the genus Thermococcus. Phylogenetic analyses indicated that the strain is most closely related to Thermococcus barossii DSM17882T based on its 16S rRNA gene sequence, and to ‘Thermococcus onnurineus’ NA1 based on its whole genome sequence. The average nucleotide identity scores with these strains are 77.66% for T. barossii and 84.84% for ‘T. onnurineus’, respectively. The novel isolate grows chemoorganoheterotrophically, preferentially in the presence of sulphur species. The novel isolate is piezophilic. Its growth is optimal at 75°C, pH 6.0 and under a pressure of 50 MPa. It possesses the broadest hydrostatic pressure range for growth ever described for a microorganism, growing effectively from atmospheric pressure to at least 120 MPa, and with difficulty up to 130 MPa. No other (micro)-organism isolated so far possesses such a broad pressure range for growth, whether among psychrophiles, mesophiles or hyperthermophiles. This strain exhibits a wide physiological flexibility, allowing it to cope with the harsh physical gradients found at deep-sea hydrothermal vents. Its phenotypical and phylogenetic features, together with its whole genome sequence, clearly indicate that it represents a novel species of the genus Thermococcus, for which the name Thermococcus piezophilus sp. nov., is proposed, in reference to the depth of its source location. This strain represents an excellent model of archaea to study microbial adaptation to hydrostatic pressure at high temperatures.
[1] C. Dalmasso, P. Oger, G. Selva, D. Courtine, S. L’Haridon, A. Garlaschelli, E. Roussel, J. Miyazaki, J. Reveillaud, M.Jebbar, K. Takai, L. Maignien, et Alain, Karine, « Thermococcus piezophilus sp. nov., an hyperthermophilic archaeon with a broad pressure range for growth, isolated from the Mid-Cayman Rise », Syst. Appl. Microbiol.(Submited) [2] C. Dalmasso, P. Oger, D. Courtine, M. Georges, K. Takai, L. Maignien, et K. Alain, « Complete Genome Sequence of the Hyperthermophilic and Piezophilic Archaeon Thermococcus piezophilus CDGST, able to grow under Extreme Hydrostatic Pressures », Genome Announc.10.1128/genomeA.00610-16
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Session 7. O-18 Genomics uncovers the functional potential of microbial communities in deep-sea hydrothermal vent sediments.
Nina Dombrowski, Kiley W. Seitz, Andreas P. Teske, Brett J. Baker* University of Texas Austin, Marine Science Institute.
Deep-sea sedimentary environments represent one of the largest reservoirs of carbon and microbial life on the planet and are crucial to our understanding of biogeochemical nutrient cycles. Sediments proximal to Guaymas Basin deep-sea hydrothermal vents host a vast diversity comprising more than 50 phyla based on rRNA gene sequencing. Despite our knowledge about the geochemistry and microbial community composition in Guaymas Basin deep-sea sediments, we lack a detailed understanding about how metabolic capacities are partitioned across these microbial lineages. To address this gap, we employed metagenomic sequencing of microbial communities inhabiting these sediments. Genomic assembly and binning of four different sediment cores resulted in the reconstruction of 131 high-quality genomes, representing 15 archaeal and 21 bacterial phyla. Several widespread bacterial taxa genomes were obtained including; Chloroflexi, Planctomycetes, KSB1, Deltaproteobacteria, TA06, WOR-3, Cloacimonas, and candidate phyla radiation (CPR). The archaeal genomes belong to Archaeoglobales, Aenigmarchaeota, Thermoplasmatales, Bathyarchaeota, and several DPANN phyla. Interestingly, we have also obtained members of the new ASGARD superphylum (Odinarchaeota and Heimdallarchaeota), which share a common ancestor with eukaryotes. Inference of physiologies from these genomes revealed the present of pathways for nitrogen and sulfur cycling (i.e. Desulfobacteriales and Beggiatoa), symbiotic relationships (i.e. OP1), and fermentation (members of the Candidate Phyla Radiation, WOR-3). The archaea, notably ASGARD, appear to be primarily involved in the degradation and fermentation of detrital organic matter (eg. proteins and lipids). Not surprisingly, the taxonomic structure of these two communities is disparate. However, we detected a substantial functional overlap between the communities inhabiting these two environmentally distinct sediment sites, for example in the occurrence of two-component secretion systems. Our study uncovers the functional potential of microbes driving nutrient cycling in Guaymas Basin deep-sea sediments as well as a functional overlap with bacteria from shallow estuary sediments, hinting for an adaptation to similar environmental driving cues.
O-19 Metabolic potential of uncultured bacteria in massive sulfide deposits below the deep seafloor revealed by metagenomic analyses.
Shingo Kato1 and Katsuhiko Suzuki1 1Ore Genesis Research Unit (SIP), JAMSTEC, Kanagawa, Japan.
Sulfide deposits usually containing pyrite (FeS2) are created on marine hydrothermal fields by mixing of reduced hot fluids and oxygenated cold seawater. Even if the hydrothermal activity ceases, some sulfide deposits persist for several thousand years or more, and can support chemosynthetic microbial ecosystems as energy sources in the cold and dark environments. Considering the vast amount of the sulfide deposits on and below the seafloor, the chemosynthetic ecosystem sustained by the sulfide deposits might be one of the largest chemosynthetic ecosystems on Earth. However, little is known about the microbial ecosystems in the hydrothermally inactive, cold sulfide deposits, in contrast to those in hydrothermally active, hot environments. Recently, we collected samples of massive sulfide deposits (up to 2.67 m depth below the seafloor) using a seafloor coring instrument in deep-sea hydrothermal fields of the Southern Mariana Trough, and reported the presence of uncultured members of Actinobacteria, Bacteroidetes, Ignavibacteriae, Nitrospinae, Nitrospirae, Deltaproteobacteria, Gammaproteobacteria and Zetaproteobacteria, which potentially drive iron, sulfur, nitrogen and carbon cycling in the sub-seafloor sulfide deposits (1). However, their abundance and metabolic functions are still unclear. To this end, we have performed metagenomic analyses of the samples in the present study. The metagenomic data have shown that members in Gammaproteobacteria and Zetaproteobacteria are abundant in the shallower sample, and that, in contrast,
21 DSM 2016, Kyoto members in Nitrospirae are abundant in the deeper samples, which are consistent with the previous 16S rRNA gene analyses. Furthermore, we have obtained metagenomic bins of some of these uncultured members with their 16S rRNA genes, and found metabolic pathways of carbon fixation, nitrogen fixation, sulfide oxidation, sulfate reduction, thiosulfate oxidation and reduction, nitrite oxidation, denitrification and nitrate reduction in the bins of the uncultured members.
(1) Kato et al. (2015) Environmental Microbiology 17: 1817-35.
O-20 Discovery of bacteriophages amongst the order of Thermotogales.
Mercier Coraline1, Lossouarn Julien1, Dupont Samuel1, Bienvenu Nadège1, Baudoux Anne-Claire2,3, Haverkamp H.A Thomas4, Jebbar Mohamed1, Nesbø L. Camilla4,5, Geslin Claire1 1Université de Bretagne Occidentale (UBO), LM2E UMR6197 IUEM, Plouzané France 2Sorbonne Universités, UPMC Univ Paris 06, UMR 7144, Equipe DIPO, Station Biologique de Roscoff, 29680 Roscoff, France 3CNRS, UMR 7144, Adaptation et Diversité en Milieu Marin, Station Biologique de Roscoff, 29680 Roscoff, France 4Centre for Ecological and Evolutionary Synthesis, University of Oslo, Oslo, Norway 5University of Oslo and University of Alberta, Edmonton AB Canada
Our knowledge of the viral diversity associated to the microorganisms inhabiting the deep-sea hydrothermal vents is still limited. Only a few studies have focused on viral abundance and impact on microbial mortality within these ecosystems. A limited number of viruses (6 bacterioviruses and 2 archaeoviruses) were isolated from these environments and characterized. Two viruses associated to hyperthermophilic anaerobic Archaea, from the Thermococcales order, have been described in our laboratory. In order to deepen our knowledge on the viral diversity of these extreme environments, we have extended our investigation to the bacterial order of Thermotogales. This order is composed of anaerobic chemoorganotrophic bacteria that are, for the most part, hyper/thermophilic. Numerous lateral gene transfers have contributed to the evolutionary history of the Thermotogales, implying the potential involvement of viruses. Here, we will report the characterization and a comparison of the three new viruses infecting Thermotogales. The first virus infecting bacteria from the order Thermotogales, is Marinitoga piezophila virus 1 (MPV1), a temperate siphovirus infecting a piezophilic host isolated from the East Pacific Rise. We also reported that this bacteriovirus shares its host with a plasmid of 13.3 kb (pMP1). This element is preferentially packaged by the viral capsid and can spread in a new host. This new example of molecular piracy highlights potential relevance of selfish genetic elements in facilitating lateral gene transfer in the deep-sea biosphere [4]. During further investigations, two new viruses infecting Thermotogales were discovered and characterized (Mercier et al., in preparation). The two siphoviruses MCV1 and MCV2 infect two strains of Marinitoga camini. Those bacterial strains were isolated from two deep-sea hydrothermal vents sites (Menez Gwen and Lucky strike) in the Mid Atlantic Ridge. The three viruses (MPV1, MCV1 and MCV2) are temperate with a high basal production of virions (>107 virions/mL). In the extreme environments, proviruses and lysogenic cycle could contribute to the fitness of the host strains whereas for the virus, the integrated state represents a means to avoid the harsh conditions of these ecosystems. A comparison of the three viral genomes was done and even if the hosts’ strains come from different oceans, genomes present numerous similarities. More than 68% of Marinitoga camini viruses’ genomes are identical including helicases, transcriptional regulators and holin proteins. A strong similarity with MPV1 was also shown (64% of identity with MCV2 and 56% of identity with MCV1). The genomes of the bacterioviruses reported in this study reveal also a connection to genomes of Firmicutes and bacterioviruses known to infect them. Because Thermotogales and Firmicutes appear to share large number of genes, our findings imply that viruses may have mediated some of these genes exchanges.
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O-21 Large-scale distribution of microbial and viral populations in the South Atlantic Ocean.
1,2 2 1 2 Daniele De Corte , Eva Sintes , Taichi Yokokawa , Gerhard J. Herndl . 1Marine Functional Biology Group, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan 2Department of Limnology and Bio-Oceanography, University of Vienna, Vienna, Austria.
Viruses are abundant, diverse and a dynamic component of marine ecosystems. Viruses play a key role in the biogeochemical processes of the ocean by controlling prokaryotic and phytoplankton abundance and diversity. However, most studies on virus – microbe interactions in marine environments have been conducted in near shore waters. To assess potential variations in the relation between viruses and microbes in different oceanographic provinces and depth horizons, we determined viral and microbial abundance and production throughout the water column along a latitudinal transect in the Atlantic Ocean. Microbial and viral abundance, and heterotrophic activity decreased by one and three orders of magnitude, respectively, from the epi- (0-150 m depth) to the abyssopelagic layer (below 4000m depth). Virus-to-microbial ratio, increased from ~19 in surface waters to ~53 in the bathy- and abyssopelagic realm. The lytic viral production also decreased with depth. Lysogenic viral production did not exhibit specific trends with depth, however, it increased in its relative contribution to overall viral production from subpolar regions towards the more oligotrophic lower latitudes. Our data revealed that the abundance of phytoplankton and microbes is the main controlling factor of the viral populations in the euphotic and mesopelagic layers, whereas in the bathypelagic realm, viral abundance was only weakly related to the biotic and abiotic variables.
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Session 8. O-22 Brucite-carbonate chimneys discovered in the Shinkai Seep Field, a serpentinite-hosted vent system in the Southern Mariana Forearc.
Tomoyo Okumura1, Ken Takai1, Miho Hirai1, Yasuhiko Ohara1,2 1Department of Subsurface Geobiological Analysis and Research, Japan Agency for Marine-Earth Science & Technology, Yokosuka, Japan. 2Hydrographic and Oceanographic Department of Japan, Tokyo, Japan.
Serpentinite-hosted hydrothermal systems have attracted great interest as unique modern deep-sea chemosynthetic ecosystems and as an analogue for the origin and early evolution of Hadean life since the discovery of the Lost City hydrothermal field (LCHF; Kelley et al., 2001). During expeditions by Shinkai 6500 since 2013 to 2015, brucite-carbonate chimneys were discovered from the deepest known (~5700 m depth) serpentinite-hosted ecosystem – the Shinkai Seep Field (SSF) in the southern Mariana forearc. Here we report geobiological characteristics of the SSF chimney, as new types of microbial habitat at a serpentinite-hostet vent system. Textural observations and geochemical analysis reveal three types (I-III) of chimneys formed by the precipitation and dissolution of constitutive minerals. Type I chimneys are bright white to light yellow, have a spiky crystalline and wrinkled surface with microbial mat and contain more brucite; these formed as a result of rapid precipitation under high fluid discharge conditions. In this type of chimneys, filamentous microbial cells were often mineralized by brucite. Type II chimneys exhibit white to dull brown coloration, tuberous textures like vascular bundles, and are covered with grayish microbial mats and dense colonies of Phyllochaetopterus. This type of chimney is characterized by inner brucite-rich and outer carbonate rich zones and is thought to have precipitated from lower fluid discharge conditions than type I chimneys. Type III chimneys are ivory colored, have surface depressions and lack living microbial mats or animals. This type of chimney mainly consists of carbonate, and is in a dissolution stage. Tag-sequencing analysis for the small subunit (SSU) rRNA gene showed the microbial compositions varied with the chimney types reflecting the hydrologic and biological processes of the SSF vent system. Some geobiological features of the SSF chimneys are distinctive from those in the LCHF. Our findings reveal the variability of subseafloor and seafloor geochemical and geobiological processes in the global deep-sea serpentinite-hosted hydrothermal and seepage systems.
O-23 Population genetics and phenotypic differences of cosmopolitan mesophilic Sulfurimonas at deep-sea hydrothermal vents.
Sayaka Mino1, Satoshi Nakagawa2,3, Hiroko Makita3, Junichi Miyazaki3, Stefan M. Sievert4, Martin F. Polz5, Fumio Inagaki6,7, Anne Godfroy8, Shingo Kato9, Takuro Nunoura10, Hiroyuki Imachi3, Ken Takai3, and Tomoo Sawabe1 1Faculty of Fisheries Sciences, Hokkaido University, Hakodate, Japan. 2Graduate School of Agriculture, Kyoto University, Kyoto, Japan. 3Department of Subsurface Geobiology Analysis and Research, JAMSTEC, Yokosuka, Japan. 4Biology Department, WHOI, MA, USA. 5Department of Civil and Environmental Engineering, MIT, MA, USA. 6Kochi Institute for Core Sample Research, JAMSTEC, Nankoku, Japan. 7Research and Development Center for Ocean Drilling Science, JAMSTEC, Yokohama, Japan. 8Laboratoire de Microbiologie des Environnements Extrêmes, Ifremer, Plouzané, France. 9Japan Collection of Microorganisms, RIKEN, Tsukuba, Japan. 10Research and Development Center for Marine Biosciences, JAMSTEC, Yokosuka, Japan.
The characterization of geographical distribution is of fundamental importance to understand the factors for driving biodiversity of both deep-sea vent animals and microorganisms. Although deep-sea vent macrofauna exhibit a clear geographical isolation, the corresponding knowledge about deep-sea vent microorganisms are lagging.
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Members of the genus Sulfurimonas (class Epsilonproteobacteria) represent good model for testing the dispersal capability due to their cosmopolitan distribution at deep-sea hydrothermal environments. We applied multilocus sequence analysis (MLSA) to assess the genetic variation of closely related Sulfurimonas strains isolated from four geographical regions (Okinawa Trough, Mariana Volcanic Arc and Trough, Central Indian Ridge, and Mid-Atlantic Ridge). Sequence typing based on 11 protein-coding genes showed that the allelic diversity varied at regional scales, indicating the limited dispersal. In addition, the genetic diversity was correlated to the geographical distances rather than environmental factors such as depth and gas composition of vent fluids. Our results suggested the allopatric speciation in cosmopolitan Sulfurimonas population. In this study, we would like to discuss the dispersal capability and possibility of the correlation between Sulfurimonas metabolic traits and environmental characteristics.
O-24 New catabolic processes that can fuel anaerobic deep-sea hydrothermal ecosystems.
Alexander Slobodkin, Galina Slobodkina, Tatyana Sokolova, Alexander Lebedinsky, Elizaveta Bonch-Osmolovskaya Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow, Russia
Molecular hydrogen is considered to be the main energy source that can fuel anaerobic microbial ecosystems in natural thermal environments including deep-sea hot vents. However, we found that there are other catabolic reactions in which energy substrates of abiotic origin could be used by anaerobic prokaryotes. Thermophilic bacteria isolated from the deep-sea hot vents were found to be able to use the energy of sulfur compounds – elemental sulfur, thiosulfate and sulfite – in the reaction of disproportionation, producing hydrogen sulfide and sulfate. The first isolate of this group was Thermosulfurimonas dismutans gen.nov., sp. nov., belonging to the phylum Thermodesulfobacteria. It was obtained from a deep-sea hydrothermal vent chimney located on the Eastern Lau Spreading Center, Pacific Ocean, at a depth of 1910 m and was find to grow in the temperature range from 50 to 92 °C, with an optimum at 74 °C, and at a circumneutral pH, by the disproportionation of elemental sulfur, thiosulfate and sulfite, with bicarbonate as the carbon source. Another autotrophic sulfur-disproportionating thermophilic isolate obtained from a deep-sea hydrothermal vent chimney – Dissulfuribacter thermophilus gen. nov., sp. nov., was a moderate thermophile with the temperature growth optimum at 61 °C and formed a distinct phylogenetic branch within the Deltaproteobacteria. C1-compounds, such as CO or formate, that can be formed in the course of serpentinization process, could serve as the energy sources for numerous Thermococcales. CO and formate can be either used in the course of hydrogenogenic growth, or serve as the substrates for the elemental sulfur reduction to hydrogen sulfide. Though our deep-sea isolates turned to be the first sulfur-disproportionating thermophiles, we found the members of this phylogenetically divergent metabolic group in other types of thermal environments, such as terrestrial or shallow-water hot vents. Hydrogenotrophic growth on CO is also a feature of many thermophilic prokaryotes, but C1-utilizing Thermococcales known so far are only of the deep-sea origin.
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Poster presentation
P-1 Genomic analysis of an extremely piezophilic Shewanella benthica DB21MT-2 isolated from the Mariana Trench.
Xue-Gong Li1, Wei-Jia Zhang1, Long-Fei Wu1,2 1Deep-sea microbial cell biology, Department of Deep Sea Sciences, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China 2Aix-Marseille Université, CNRS, LCB UMR 7257, IMM, 31, chemin Joseph Aiguier, F-13 13402, Marseille, France
Hadal zone (6000-11000m) represented the deepest habitats on the surface of the earth, where the hydrostatic pressure is a key physical parameter in the biosphere. Relatively few studies have described the microorganisms in hadal environments and genomic characteristics underlying the adaptive strategy in such environment are poorly understood. Shewanella benthica DB21MT-2 is a psychrophilic and extremely piezophilic gamma-proteobacterium that was isolated from the deep-sea sediment at a depth of 10898 m in the Mariana Trench. The genome of S. benthica DB21MT-2 has been sequenced and compared with the genome of the non-piezophilic S. oneidensis MR1. The results showed that S. benthica DB21MT-2 possesses few terminal reductases for anaerobic respiration. Both MR1 and DB21MT-2 genomes contain Fe (III) reductase, periplasmic nitrate reductase (Nap-β), cytochrome c552 nitrite reductase (NrfA), periplasmic fumarate reductases, and trimethylamine-N-oxide (TMAO) reductase, although the S. benthica DB21MT-2 genome possesses few number of reductase related to Fe(III) reduction and TMAO reduction. Whereas membrane-bound fumarate reductases and dimethyl sulfoxide reductase only found in the S. oneidensis MR1 genome. Moreover, MR1 and DB21MT-2 genome contain the different type of Nap, Nap-α (napDABC) for S. benthica DB21MT-2 and Nap-β (napDAGHB) for S. oneidensis MR1, respectively. In contrast, S. benthica DB21MT-2 genome contains more terminal oxidases for aerobic respiration. In addition, S. benthica DB21MT-2 genomes also contains more genes with transporters and assimilatory reductases for nitrate and nitrite, and nitric oxide-detoxifying. The genome sequence of S. benthica DB21MT-2 revealed the respiratory adaptation of this bacterium and help to understand the mechanism of the piezophilic adaptation mechanism of deep-sea piezophiles.
P-2 Effect of TMAO on piezophilic growth of marine bacteria.
Qun-Jian YIN1,3, Wei-Jia ZHANG1,3, Sheng-Da ZHANG1,3, Ting Jiang1,3 and Long-Fei WU2,3 1Deep-sea microbial cell biology, Department of Deep Sea Sciences, Institute of Deep-Sea Science and Engineering, Chinese Academy of Sciences, Sanya, China. 2LCB UMR 7257, Aix-Marseille Université, CNRS, IMM, 31, Chemin Joseph Aiguier, 13402 Marseille Cedex 20, France. 3France-China Bio-Mineralization and Nano-Structure Laboratory (LIA-BioMNSL), LCB-CNRS, Marseille, France/IDSSE-CAS, Sanya, China.
The deep sea constitutes the largest habitat in the biosphere, is characterized by low temperature, restricted organic carbon, and high hydrostatic pressure. Bacteria with better growth rate under high pressure are assigned as piezophiles. Trimethylamine N-oxide (TMAO) is well known as osmolyte and protein stabilizer. It is commonly found in the marine environment and abundant in the muscle tissues and plasma of marine fish and invertebrates. Accumulation of TMAO in fish tissues is proportional with depth, indicating an important role in the high-pressure adaptation of deep-sea fishes. TMAO also serves as an electron acceptor in bacteria for generating energy via anaerobic respiration. To contribute to a better understanding of piezophilic growth of deep-sea bacteria and the effect of TMAO on high-hydrostatic pressure adaptation, we collected sea water samples from the China Sea at various depths. Phylogenetic analysis based on 16S rRNA genes have identified isolated strains belonging to Photobacterium, Pseudoalteromonas, Alteromonas and Vibrio. They displayed piezophilic, piezotolerant and piezosensitive phenotypies.
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TMAO metabolism capacity of those bacteria differs from Genus. Strains of Vibrio and Photobacterium can utilize TMAO for growth while those of Pseudoalteromonas and Alteromonas cannot. Vibrio fluvialis QY27 is a piezosensitive bacterium isolated from 2,500 m below the seawater surface. Addition of TMAO in growth media slightly increased its growth under 0.1MPa, but significantly promoted under 30 MPa, showing a piezophilic phenotype. Results of Electrospray ionization Quadrupole-Time of Flight (ESI-Q-TOF) and molecular analysis revealed two TMAO reductases in the strain QY27. TMAO respiration seems play an important role in the adaptation of the V. fluvialis QY27 to high hydrostatic pressure.
P-3 The euarchaea DNA replication fork contains two copies of DNA polymerase D.
Shuhong Lu1,2, Zimeng Chen1, Zhuo Li1 1Third Institute of Oceanography, State Oceanographic Administration of China, Xiamen, China. 2College of Oceanography, Xiamen University, Xiamen, China.
As the third domain of life, archaea was known to be living in extreme environments. Although a lot of archaeal DNA replication genes are similar but simpler to their eukaryotic counterparts, the rest of them are archaea specific. Through more than two decades studies, people learned the archaeal DNA replication core is composed of tens of proteins, which are deliberately coordinated. The genomes of euarchaea contain at least two DNA polymerases named DNA polymerase B (PolB) and DNA polymerase D (PolD). The later is an archaea specific DNA polymerase, which was found in the same complex with a serial of DNA replication proteins including GINS and GAN. More importantly, PolD was recently revealed to be essential for the viability of Thermococcus kodakarensis. To better understand the stoichiometry and hence to reveal the mechanism of DNA replication of archaea, we studied the PolD complexes using a combination of biochemistry, biophysics and genetics approaches. We found DP1, the small subunit of PolD, interacts with GINS15 (the eukaryotic Sld5, Psf1 homologues in archaea). In addition to physical interaction, the 3 to 5 exonuclease activity of DP1 is specifically inhibited by GINS15, but not GINS23 (the eukaryotic Psf2 and Psf3 homologues in archaea). The previous studies found GINS15 and GINS23 exist in a GINS152-GINS232 composition; it will be reasonable to speculate that the archaeal DNA replication core contains two DP1s. Also, DP1 and DP2 were known to work in a hetero dimmer. Based on the previous study and the observations in this study, we proposed a model of euarchaea DNA replication core that contains at least two copies of PolD. This model resembles the E. coli. DNA replication core containing two copies of PolIII.
P-4 Difference in salt stability of membrane-bound 5’-nucleotidases purified from piezophilic, moderately-halophilic and piezosensitive, non-halophilic Shewanella species.
Takaaki Kuribayashi1, Sotaro Fujii1, Satoshi Wakai2 and Yoshihiro Sambongi1 1Graduate School of Biosphere Science, Hiroshima University, Hiroshima, Japan. 2Graduate School of Science, Technology, and Innovation, Kobe University, Hyogo, Japan.
Shewanella species are widely distributed in fresh-, brackish, and seawater environments. Not only surface area on the Earth, some Shewanella species live in deep-sea areas. This wide distribution of Shewanella species makes them suitable bacteria for investigating not only the enzymatic reactions that drive biogeochemical cycles but also the protein stability mechanism as to such various environments. 5’-nucleotidase (NTase) is a widespread enzyme and appears to function as a nutrient-acquiring enzyme on the periphery of bacteria. It is also an enzyme involved in extracellular nucleotide signaling and degradation in mammals and in human pathogenic bacteria. NTase from Vibrio species have unveiled basic enzymology such as substrate and cation specificities. As most Vibrio species had been isolated from sea surface environments, the effects of salts such as NaCl and KCl on their
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NTase activities were investigated, but a comparative study on the salt stability mechanism of the enzymes has not been performed. In this study, we purified two homologous membrane-bound NTases. One is from piezophilic, moderately-halophilic Shewanella violacea strain DSS12 isolated from sea-water sediments of the Ryukyu Trench at the depth of 5,110 m, which grows optimally with ~0.51 M NaCl, but shows no growth in the absence of NaCl. The other one was from piezosensitive, non-halophilic Shewanella amazonensis strain SB2B isolated from brackish water deposits of Amazon River Delta at the depth of 0 m, which grows optimally with ~0.2 M NaCl and even grows in the absence of NaCl, but not with~0.51 M. The two NTases derived from such distinctive salt environmental niches were characterized in this study. They showed a remarkable difference in salt stability, which will be discussed as to protein stability.
P-5 Epibiosis insights associated with deep-sea hydrothermal vent shrimp Rimicaris exoculata revealed by metagenomics and metatranscriptomics.
Lijing Jiang, Chunming Dong, Zhaobin Huang and Zongze Shao* Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA, Xiamen, China
The shrimp Rimicaris exoculata living in the deep-sea hydrothermal vents hosts a dense epibiotic community of chemoautotrophic bacteria on the enlarged gill chamber. Yet our understanding of the shrimp-epibiont symbiosis is heavily hampered by our inability to cultivate the main microbes in the community. Here, we use a coordinated metagenomic and metatranscriptomic to characterize the microbial composition and function in the gill chamber epibiont communities of R. exoculata habitated in the South Mid-Atlantic Ridge (SMAR). Our previous study indicated a low microbial diversity and an Epsilonproteobacterial group dominated the R. exoculata epibiont based on pyrosequencing analysis of the 16S rRNA genes. De novo metagenomic assembly was used to reconstruct genomes of abundant populations. A total of 5 draft genomes were successfully obtained, of which 3 belonged to Sulfurovum (Epsilonproteobacteria) and the others belonged to Leucothrix (Gammaproteobacteria) and Desulfobulbus (Deltaproteobacteria). Sulfurovum- and Leucothrix-liked group have been identified as the dominant filamentous epibiont of R. exoculata in previous researches. Then, mapping transcripts to these genomes revealed abundant expression of genes involved in the chemolithotrophic oxidation of sulfur hydrogen and ammonia. This study is the first complete genome analysis of epibionts associated with deep-sea hydrothermal vent shrimp and offers an opportunity to study the metabolism and symbiosis of the major epibionts with their host.
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http://www.syn-c.com
High Pressure Microscopic Cell
PC-100-2-0.6-MS
The PC-100-0.6-MS is an optical cell for microscopic measurement under 100 MPa. The sapphire window have Φ2mm open witdh and abailable for NA=0.6 WD=3mm objective lenze. The cell tempearture is conntroled by installed water circulation tubing (or cartridge heater: option) .. ■specifications optical cell for microscopic measurement PC-100-2-0.6MS Max Press. 100 MPa Max. temp 80 ℃ body Material SUS630 or Ti Size 50mm x 51mm x 16mm Cell length 0.01-0.05 ｍｍ (controlled by Shim ) Window Material sapphire Open angle Objective Lenz 38° （NA=0.6) Condenser Lenz 30° Temp. control Water circulation / cartridge heater (option) Price (JPN) ￥2,000,000
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