Microbial Morphology and Motility As Biosignatures for Outer Planet Missions
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Glossary - Cellbiology
1 Glossary - Cellbiology Blotting: (Blot Analysis) Widely used biochemical technique for detecting the presence of specific macromolecules (proteins, mRNAs, or DNA sequences) in a mixture. A sample first is separated on an agarose or polyacrylamide gel usually under denaturing conditions; the separated components are transferred (blotting) to a nitrocellulose sheet, which is exposed to a radiolabeled molecule that specifically binds to the macromolecule of interest, and then subjected to autoradiography. Northern B.: mRNAs are detected with a complementary DNA; Southern B.: DNA restriction fragments are detected with complementary nucleotide sequences; Western B.: Proteins are detected by specific antibodies. Cell: The fundamental unit of living organisms. Cells are bounded by a lipid-containing plasma membrane, containing the central nucleus, and the cytoplasm. Cells are generally capable of independent reproduction. More complex cells like Eukaryotes have various compartments (organelles) where special tasks essential for the survival of the cell take place. Cytoplasm: Viscous contents of a cell that are contained within the plasma membrane but, in eukaryotic cells, outside the nucleus. The part of the cytoplasm not contained in any organelle is called the Cytosol. Cytoskeleton: (Gk. ) Three dimensional network of fibrous elements, allowing precisely regulated movements of cell parts, transport organelles, and help to maintain a cell’s shape. • Actin filament: (Microfilaments) Ubiquitous eukaryotic cytoskeletal proteins (one end is attached to the cell-cortex) of two “twisted“ actin monomers; are important in the structural support and movement of cells. Each actin filament (F-actin) consists of two strands of globular subunits (G-Actin) wrapped around each other to form a polarized unit (high ionic cytoplasm lead to the formation of AF, whereas low ion-concentration disassembles AF). -
Motility in Prokaryotes O Bacterial Flagella O Gliding Motility O Chemosensing · Movement of Materials Within Bacteria and Cell Size · Magnetotactic Bactertia
Biology of the Prokaryotes The following is a series of essays on selected aspects of prokaryote biology. These essays are ongoing, and the references are periodically updated, so do not assume completion (not that such works can ever be complete). The following topics are covered: · Motility in Prokaryotes o Bacterial flagella o Gliding motility o Chemosensing · Movement of materials within bacteria and cell size · Magnetotactic bactertia Motility in Prokaryotes 1. Motility Mode 1 - Bacterial Flagella 1.1 Introduction Some bacteria are non-motile, relying entirely upon passive flotation and Brownian motion for dispersal. However, most are motile; at least during some stage of their lifecycle. Motile bacteria move with "intent", gathering in regions which are hot or cold, light or dark, or of favourable chemical/nutrient content. This is obviously a useful attribute. Many species glide across the substratum. This may involve specific organelles, such as the filament bearing goblet-shaped structures in the walls of Flexibacter (Moat, 1979). Often, however, no specific organelles appear to be involved and gliding may be attributable to the slime covering of some bacteria or the streaming of outer membrane lipids of others (e.g. Cytophaga (Moat, 1979)) or to other mechanisms currently being elucidated (see section 2). The spiral-shaped Spiroplasma corkscrews its way through the medium by means of membrane-associated fibrils resembling eukaryotic actin (Boyd, 1988). Gonogoocci exhibit twitching motility (intermittent, jerky movements) due to the presence of pili (fine filaments, 7 nm diameter, less than one micrometer long) which branch and rejoin to form an irregular surface lattice. However, more than half of motile bacteria use one or more helical, whip-like appendages, about 24 nm diameter and up to 10 mm long, called flagella (sing. -
Patterns of Bacterial Diversity in the Marine Planktonic Particulate Matter Continuum
The ISME Journal (2017) 11, 999–1010 © 2017 International Society for Microbial Ecology All rights reserved 1751-7362/17 www.nature.com/ismej ORIGINAL ARTICLE Patterns of bacterial diversity in the marine planktonic particulate matter continuum Mireia Mestre, Encarna Borrull, M Montserrat Sala and Josep M Gasol Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSIC. Barcelona, Catalunya, Spain Depending on their relationship with the pelagic particulate matter, planktonic prokaryotes have traditionally been classified into two types of communities: free-living (FL) or attached (ATT) to particles, and are generally separated using only one pore-size filter in a differential filtration. Nonetheless, particulate matter in the oceans appears in a continuum of sizes. Here we separated this continuum into six discrete size-fractions, from 0.2 to 200 μm, and described the prokaryotes associated to each of them. Each size-fraction presented different bacterial communities, with a range of 23–42% of unique (OTUs) in each size-fraction, supporting the idea that they contained distinct types of particles. An increase in richness was observed from the smallest to the largest size- fractions, suggesting that increasingly larger particles contributed new niches. Our results show that a multiple size-fractionation provides a more exhaustive description of the bacterial diversity and community structure than the use of only one filter. In addition, and based on our results, we propose an alternative to the dichotomy of FL or ATT lifestyles, in which we differentiate the taxonomic groups with preference for the smaller fractions, those that do not show preferences for small or large fractions, and those that preferentially appear in larger fractions. -
Oscar Elton Sette
I MINA'TRENTA NA LIHESLATURAN GtiAHAN 2010 (SECOND) Regular Session Resolution No. 324-30 (COR) Introduced by: R. J. Respicio Judith P. Guthertz, DPA T. C. Ada F. B. Aguon, Jr. V. Anthony Ada F. F. Bias, Jr. E. J.B. Calvo B. J.F. Cruz J. V. Espaldon T. R. Mufia Barnes Adolpho B. Palacios, Sr. v. c. pangelinan Telo Taitague Ray Tenorio Judith T. Won Pat, Ed.D. Relative to recognizing and commending the Scientists, Commanding Officer and Crew of the NOAA Ship, Oscar Elton Sette, and to extending Un Dangkolo na Si Yu' OS Ma' ase' to them for their important work in investigating fishery resources and examining oceanographic and ecological characteristics of the oceans surrounding Guam, the CNMI and Micronesia. 1 1 BE IT RESOLVED BY THE COMMITTEE ON RULES OF I 2 MINA'TRENTA NA LIHESLATURAN GuAHAN: 3 WHEREAS, prominent scientists from the National Marine Fisheries 4 Service, the University of Hawaii, the University of Washington, Scripps 5 Institution of Oceanography, Woods Hole Oceanographic Institution, Western 6 Washington University, Macalester College, Cascadia Research and the 7 University of Guam, along with independent scientists, are undertaking 8 important work to study the resources and oceans surrounding Guam, the 9 Commonwealth of the Northern Mariana Islands and Micronesia; and 10 WHEREAS, the Captain and Crew of the NOAA vessel, Oscar Elton 11 Sette, which is home-ported in Hawaii, provide shipboard services for the 12 scientific investigation during the fifty-eight (58) day scientific cruise; and 13 WHEREAS, the first phase -
Comparative Saturn-Versus-Jupiter Tether Operation
Journal of Geophysical Research: Space Physics Comparative Saturn-Versus-Jupiter Tether Operation J. R. Sanmartin1 ©, J. Pelaez1 ©, and I. Carrera-Calvo1 Abstract Saturn, Uranus, and Neptune, among the four Giant Outer planets, have magnetic field B about 20 times weaker than Jupiter. This could suggest, in principle, that planetary capture and operation using tethers, which involve B effects twice, might be much less effective at Saturn, in particular, than at Jupiter. It was recently found, however, that the very high Jovian B itself strongly limits conditions for tether use, maximum captured spacecraft-to-tether mass ratio only reaching to about 3.5. Further, it is here shown that planetary parameters and low magnetic field might make tether operation at Saturn more effective than at Jupiter. Operation analysis involves electron plasma density in a limited radial range, about 1-1.5 times Saturn radius, and is weakly requiring as regards density modeling. 1. Introduction All Giant Outer planets have magnetic field B and corotating plasma, allowing nonconventional exploration. Electrodynamic tethers, which are thermodynamic (dissipative) in character, can 1. provide propellantless drag both for deorbiting spacecraft in Low Earth Orbit at end of mission and for planetary spacecraft capture and operation down the gravitational well, and 2. generate accompanying, useful electrical power, or store it to later invert tether current (Sanmartin et al., 1993; Sanmartin & Estes, 1999). At Jupiter, tethers could be effective because its field B is high (Sanmartin et al., 2008). Tethers would allow a variety of science applications (Sanchez-Torres & Sanmartin, 2011). The Saturn field is 20 times smaller, however, and tether operation involves field B twice, which makes that thermodynamic character manifest: 1. -
Construction and Loss of Bacterial Flagellar Filaments
biomolecules Review Construction and Loss of Bacterial Flagellar Filaments Xiang-Yu Zhuang and Chien-Jung Lo * Department of Physics and Graduate Institute of Biophysics, National Central University, Taoyuan City 32001, Taiwan; [email protected] * Correspondence: [email protected] Received: 31 July 2020; Accepted: 4 November 2020; Published: 9 November 2020 Abstract: The bacterial flagellar filament is an extracellular tubular protein structure that acts as a propeller for bacterial swimming motility. It is connected to the membrane-anchored rotary bacterial flagellar motor through a short hook. The bacterial flagellar filament consists of approximately 20,000 flagellins and can be several micrometers long. In this article, we reviewed the experimental works and models of flagellar filament construction and the recent findings of flagellar filament ejection during the cell cycle. The length-dependent decay of flagellar filament growth data supports the injection-diffusion model. The decay of flagellar growth rate is due to reduced transportation of long-distance diffusion and jamming. However, the filament is not a permeant structure. Several bacterial species actively abandon their flagella under starvation. Flagellum is disassembled when the rod is broken, resulting in an ejection of the filament with a partial rod and hook. The inner membrane component is then diffused on the membrane before further breakdown. These new findings open a new field of bacterial macro-molecule assembly, disassembly, and signal transduction. Keywords: self-assembly; injection-diffusion model; flagellar ejection 1. Introduction Since Antonie van Leeuwenhoek observed animalcules by using his single-lens microscope in the 18th century, we have entered a new era of microbiology. -
Marine Microplankton Ecology Reading
Marine Microplankton Ecology Reading Microbes dominate our planet, especially the Earth’s oceans. The distinguishing feature of microorganisms is their small size, usually defined as less than 200 micrometers (µm); they are all invisible to the naked eye. As a group, sea microbes are extremely diverse, and extremely versatile with respect to their abilities to make and eat food. All marine microbes are too small to swim against the current and are therefore classified as plankton. First we will discuss several ways to classify marine microbes. 1. Size Planktonic marine organisms can be divided into the following size categories: Category Size femtoplankton <0.2 µm picoplankton 0.2-2 µm nanoplankton 2-20 µm microplankton 20-200 µm mesoplankton 200-2000 µm In this laboratory we are concerned with the microscopic portion of the plankton, less than 200 µm. These organisms are not visible to the naked eye (Figure 1). Figure 1. Size classes of marine plankton 2. Type A. Viruses Viruses are the smallest and simplest microplankton. They range from 0.01 to 0.3 um in diameter. Externally, viruses have a capsid, or protein coat. Viruses can also have simple or complex external morphologies with tail fibers and structures that are used to inject DNA or RNA into their host. Viruses have little internal morphology. They do not have a nucleus or organelles. They do not have chlorophyll. Inside a virus there is only nucleic acid, either DNA or RNA. Viruses do not grow and have no metabolism. Marine viruses are highly abundant. There are up to 10 billion in one liter of seawater! B. -
Monday, November 13, 2017 WHAT DOES IT MEAN to BE HABITABLE? 8:15 A.M. MHRGC Salons ABCD 8:15 A.M. Jang-Condell H. * Welcome C
Monday, November 13, 2017 WHAT DOES IT MEAN TO BE HABITABLE? 8:15 a.m. MHRGC Salons ABCD 8:15 a.m. Jang-Condell H. * Welcome Chair: Stephen Kane 8:30 a.m. Forget F. * Turbet M. Selsis F. Leconte J. Definition and Characterization of the Habitable Zone [#4057] We review the concept of habitable zone (HZ), why it is useful, and how to characterize it. The HZ could be nicknamed the “Hunting Zone” because its primary objective is now to help astronomers plan observations. This has interesting consequences. 9:00 a.m. Rushby A. J. Johnson M. Mills B. J. W. Watson A. J. Claire M. W. Long Term Planetary Habitability and the Carbonate-Silicate Cycle [#4026] We develop a coupled carbonate-silicate and stellar evolution model to investigate the effect of planet size on the operation of the long-term carbon cycle, and determine that larger planets are generally warmer for a given incident flux. 9:20 a.m. Dong C. F. * Huang Z. G. Jin M. Lingam M. Ma Y. J. Toth G. van der Holst B. Airapetian V. Cohen O. Gombosi T. Are “Habitable” Exoplanets Really Habitable? A Perspective from Atmospheric Loss [#4021] We will discuss the impact of exoplanetary space weather on the climate and habitability, which offers fresh insights concerning the habitability of exoplanets, especially those orbiting M-dwarfs, such as Proxima b and the TRAPPIST-1 system. 9:40 a.m. Fisher T. M. * Walker S. I. Desch S. J. Hartnett H. E. Glaser S. Limitations of Primary Productivity on “Aqua Planets:” Implications for Detectability [#4109] While ocean-covered planets have been considered a strong candidate for the search for life, the lack of surface weathering may lead to phosphorus scarcity and low primary productivity, making aqua planet biospheres difficult to detect. -
David W. Johnston, Ph. D
135 DUKE MARINE LAB RD. BEAUFORT, NC 28516 TEL 252-504-7593 FAX 252-504-7648 EMAIL [email protected] WEB http://fds.duke.edu/db/dwj2 DAVID W. JOHNSTON, PH. D. PROFILE I am a broadly skilled biological oceanographer and conservation biologist who’s research focuses on the foraging ecology and habitat needs of marine animals in relation to pressing conservation issues. At present I have active projects in the following areas: population assessments and the oceanographic drivers of foraging ecology of marine vertebrates, the design and utility of marine protected areas; the effects of climate variability and global change on marine animals and the sustainability of incidental mortality and directed harvests of marine animals. I am also involved in projects addressing the effects of anthropogenic sound on marine mammals and the suitable application of new technological approaches to marine ecology and conservation. I have experience working in a variety of marine ecosystems - from the highly productive waters of the California Current and Bay of Fundy, to the oligotrophic waters of the central Pacific. EMPLOYMENT EXPERIENCE RESEARCH SCIENTIST, DUKE UNIVERSITY MARINE LABORATORY. JUNE 2008 TO PRESENT. DIVISION OF MARINE SCIENCE AND CONSERVATION. NICHOLAS SCHOOL OF THE ENVIRONMENT. 135 DUKE MARINE LAB RD. BEAUFORT NC 28516. Currently conducting collaborative research projects involving 1) marine predator ecology and population assessments in the shelf and slope waters of the Northwest Atlantic and the Western Antarctic Peninsula, 2) spatial modeling of marine vertebrate habitats in the Pacific and Western Antarctic Peninsula, 3) examining the effects of climate variability on the ecology of ice-associated pinnipeds in the North Atlantic and 4) assessing the diversity, stock structure and abundance of cetaceans in the Pacific Islands Region in relation to new management approaches. -
Extreme Organisms on Earth Show Us Just How Weird Life Elsewhere Could Be. by Chris Impey Astrobiology
Astrobiology Extreme organisms on Earth show us just how weird life elsewhere could be. by Chris Impey How life could thrive on hostile worlds Humans have left their mark all over Earth. We’re proud of our role as nature’s generalists — perhaps not as swift as the gazelle or as strong as the gorilla, but still pretty good at most things. Alone among all species, technology has given us dominion over the planet. Humans are endlessly plucky and adaptable; it seems we can do anything. Strain 121 Yet in truth, we’re frail. From our safe living rooms, we may admire the people who conquer Everest or cross deserts. But without technology, we couldn’t live beyond Earth’s temperate zones. We cannot survive for long in temperatures below freezing or above 104° Fahrenheit (40° Celsius). We can stay underwater only as long as we can hold our breath. Without water to drink we’d die in 3 days. Microbes, on the other hand, are hardy. And within the microbial world lies a band of extremists, organisms that thrive in conditions that would cook, crush, smother, and dissolve most other forms of life. Collectively, they are known as extremophiles, which means, literally, “lovers of extremes.” Extremophiles are found at temperatures above the boiling point and below the freezing point of water, in high salinity, and in strongly acidic conditions. Some can live deep inside rock, and others can go into a freeze-dried “wait state” for tens of thousands of years. Some of these microbes harvest energy from meth- ane, sulfur, and even iron. -
Gastrointestinal Motility Physiology
GASTROINTESTINAL MOTILITY PHYSIOLOGY JAYA PUNATI, MD DIRECTOR, PEDIATRIC GASTROINTESTINAL, NEUROMUSCULAR AND MOTILITY DISORDERS PROGRAM DIVISION OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION, CHILDREN’S HOSPITAL LOS ANGELES VRINDA BHARDWAJ, MD DIVISION OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION CHILDREN’S HOSPITAL LOS ANGELES EDITED BY: CHRISTINE WAASDORP HURTADO, MD REVIEWED BY: JOSEPH CROFFIE, MD, MPH NASPGHAN PHYSIOLOGY EDUCATION SERIES SERIES EDITORS: CHRISTINE WAASDORP HURTADO, MD, MSCS, FAAP [email protected] DANIEL KAMIN, MD [email protected] CASE STUDY 1 • 14 year old female • With no significant past medical history • Presents with persistent vomiting and 20 lbs weight loss x 3 months • Initially emesis was intermittent, occurred before bedtime or soon there after, 2-3 hrs after a meal • Now occurring immediately or up to 30 minutes after a meal • Emesis consists of undigested food and is nonbloody and nonbilious • Associated with heartburn and chest discomfort 3 CASE STUDY 1 • Initial screening blood work was unremarkable • A trial of acid blockade was started with improvement in heartburn only • Antiemetic therapy with ondansetron showed no improvement • Upper endoscopy on acid blockade was normal 4 CASE STUDY 1 Differential for functional/motility disorders: • Esophageal disorders: – Achalasia – Gastroesophageal Reflux – Other esophageal dysmotility disorders • Gastric disorders: – Gastroparesis – Rumination syndrome – Gastric outlet obstruction : pyloric stricture, pyloric stenosis • -
What Is a Microorganism?
Microbiology: What is it? ! Study of organisms who are too small to be seen without a microscope. ! Study of small organisms or microorganisms. NOT just Bacteria! ! Study of single celled organisms. The original cell biology! ! Categories & subjects based on the type of organisms: (1) Viruses – Virology (acellular) (2a) Bacteria – Bacteriology (e.g. Prokaryotes) (2b) Archea – Archeaology? (already taken) (3) Fungi – Mycology (4) Algae – Phycology (5) Protozoa – Protozoology WHAT IS A MICROORGANISM? “There is no simple answer to this question. The word ‘microorganism’ is not the name of a group of related organisms, as are the words ‘plants’ or ‘invertebrates’ or ‘fish’. The use of the word does, however, indicate that there is something special about small organisms; we use no special word to denote large organisms or medium-sized ones. - Sistrom (1969) 1 Reasons to study Microbiology: (1) Bacteria are part of us! E. coli lives in our gut and produces essential vitamins (e.g. K). (2) Infectivity & Pathogenicity; MO’s have the ability to cause disease in compromised &/or heathy hosts. (3) MO’s in the environment; Bioremediation or use of MO’s to breakdown waste compounds like oil, pesticides, etc. Mineral cycling of elements like N, S, Fe, etc. (4) Applied Microbiology or use in agriculture and industry. (5) Understand basic biological processes: Evolution, Ecology, Genetics, etc. WHY STUDY MICROBIOLOGY? “The role of the infinitely small is infinitely large.” - Louis Pasteur (1862) 2 WE ARE NOT ALONE! “We are outnumbered. The average human contains about 10 trillion cells. On that average human are about 10 times as many microorganisms, or 100 trillion cells...As long as they stay in balance and where they belong, [they] do us no harm…In fact, many of them provide some important services to us.