Hoang Xuyen Le

Total Page:16

File Type:pdf, Size:1020Kb

Hoang Xuyen Le Effects of endophytic actinobacteria on lucerne growth and the development of its N2-fixation symbiosis with rhizobia A thesis submitted for the award Doctor of Philosophy at Flinders University of South Australia Hoang Xuyen Le Department of Medical Biotechnology School of Medicine, Faculty of Medicine, Nursing and Health Sciences Flinders University of South Australia 2015 Declarations I certify that this thesis does not contain material which has been accepted for award of any degree of diploma, and to the best of my knowledge and belief it does not contain any material previously published or written by another person except where due reference is made in the text of this thesis or in the notes. Hoang Xuyen Le i Contents Declarations .............................................................................................................................. i List of tables ............................................................................................................................ ix List of figures .......................................................................................................................... xi Acknowledgment .................................................................................................................. xiii Abbreviations .........................................................................................................................xiv Abstract .................................................................................................................................. xv Chapter 1 ................................................................................................................................ 1 Introduction and Literature review ..................................................................................... 1 1.1 Global importance of legumes and nitrogen fixation ......................................................... 2 1.1.1 General information on legumes ................................................................................. 2 1.1.2 Lucerne globally and in Australia .............................................................................. 3 1.2 Importance of soil micro-flora to legume production ........................................................ 4 1.2.1 Rhizobia and nitrogen fixation .................................................................................... 4 1.2.1.1 Rhizobium spp. ..................................................................................................... 4 1.2.1.2 The nodulation process ........................................................................................ 5 1.2.1.3 Lucerne symbiosis .............................................................................................. 12 1.2.2 Effects of other soil microorganisms on plant growth and nitrogen fixation by legumes .............................................................................................................................. 12 1.2.2.1 Mycorrhiza spp. ................................................................................................. 12 1.2.2.2 Trichoderma spp. ............................................................................................... 14 1.2.2.3 Pseudomonas spp. .............................................................................................. 14 1.2.3 Endophytic actinobacteria ........................................................................................ 15 1.2.3.1 Definition of endophyte ...................................................................................... 15 1.2.3.2 General characteristics of actinobacteria and endophytic actinobacteria ........ 16 1.2.3.3 Occurrence and diversity of endophytic actinobacteria in plants ..................... 19 1.2.3.4 Evidence of actinobacterial effects on agricultural plants ................................ 21 1.2.3.5 Potential mechanisms of action ......................................................................... 24 1.3 Summary, potential for legume improvement and critical knowledge gaps. ................... 28 1.4. Research plan (Objectives) ............................................................................................. 29 1.4.1 Aims of research ....................................................................................................... 29 1.4.2 Hypothesis ................................................................................................................. 29 1.4.3 Research plan ............................................................................................................ 29 Chapter 2 .............................................................................................................................. 31 ii General materials and methods .......................................................................................... 31 2.1 Legume seeds, rhizobia and actinobacteria ...................................................................... 32 2.2 Treatment of seeds and application of inoculants ............................................................ 33 2.2.1 Surface sterilisation of seeds..................................................................................... 33 2.2.2 Isolation, growth and application of actinobacteria ................................................. 33 2.2.3 Growth of Rhizobium ................................................................................................ 34 2.2.4 Plant growth media, nutrition, sowing and water supply ......................................... 34 2.2.5 Harvest of plants ....................................................................................................... 35 2.3 Data collection and analysis ............................................................................................. 35 2.4 Identification of endophytic actinobacteria by 16S rRNA gene amplification and sequencing.............................................................................................................................. 35 2.4.1 DNA extraction ......................................................................................................... 36 2.4.2 Quantify DNA concentration .................................................................................... 37 2.4.3 PCR 16S rRNA .......................................................................................................... 37 2.4.4 Clean up and sequencing the PCR products ............................................................. 38 Chapter 3 .............................................................................................................................. 39 Isolation and characterisation of actinobacterial endophytes from pasture legumes ... 39 3.1. Introduction ..................................................................................................................... 40 3.2 Materials and methods ..................................................................................................... 42 3.2.1 Source of legumes ..................................................................................................... 42 3.2.2 Isolation of endophytic actinobacteria ...................................................................... 42 3.2.2.1 Surface-sterilization procedure .......................................................................... 42 3.2.2.2 Media for isolation ............................................................................................. 43 3.2.2.3 Purification of actinobacterial endophytes ........................................................ 43 3.2.3 Characterisation of endophytic actinobacteria ........................................................ 43 3.2.3.1 Morphology (frequency and distribution) .......................................................... 43 3.3 Results and discussion ..................................................................................................... 44 3.3.1 Isolation of endophytic actinobacteria from legumes ............................................... 44 3.3.2 Morphological characterisation of actinobacteria ................................................... 47 3.4 Conclusion ....................................................................................................................... 49 Chapter 4 .............................................................................................................................. 50 Effects of actinobacteria on lucerne germination, seedling growth, and tolerance of soil- borne disease......................................................................................................................... 50 4.1 Introduction ...................................................................................................................... 51 4.2 Materials and methods ..................................................................................................... 54 iii 4.2.1 Effects of actinobacteria on lucerne germination ..................................................... 54 4.2.1.1 Lucerne germination on agar ............................................................................ 54 4.2.1.2 Lucerne growing in a sandy loam ...................................................................... 54 4.2.2 Inhibition of the growth of pathogenic fungi on agar ............................................... 55 4.2.3 Effect of actinobacteria on the development of root damage
Recommended publications
  • View Details
    INDEX CHAPTER NUMBER CHAPTER NAME PAGE Extraction of Fungal Chitosan and its Chapter-1 1-17 Advanced Application Isolation and Separation of Phenolics Chapter-2 using HPLC Tool: A Consolidate Survey 18-48 from the Plant System Advances in Microbial Genomics in Chapter-3 49-80 the Post-Genomics Era Advances in Biotechnology in the Chapter-4 81-94 Post Genomics era Plant Growth Promotion by Endophytic Chapter-5 Actinobacteria Associated with 95-107 Medicinal Plants Viability of Probiotics in Dairy Products: A Chapter-6 Review Focusing on Yogurt, Ice 108-132 Cream, and Cheese Published in: Dec 2018 Online Edition available at: http://openaccessebooks.com/ Reprints request: [email protected] Copyright: @ Corresponding Author Advances in Biotechnology Chapter 1 Extraction of Fungal Chitosan and its Advanced Application Sahira Nsayef Muslim1; Israa MS AL-Kadmy1*; Alaa Naseer Mohammed Ali1; Ahmed Sahi Dwaish2; Saba Saadoon Khazaal1; Sraa Nsayef Muslim3; Sarah Naji Aziz1 1Branch of Biotechnology, Department of Biology, College of Science, AL-Mustansiryiah University, Baghdad-Iraq 2Branch of Fungi and Plant Science, Department of Biology, College of Science, AL-Mustansiryiah University, Baghdad-Iraq 3Department of Geophysics, College of remote sensing and geophysics, AL-Karkh University for sci- ence, Baghdad-Iraq *Correspondense to: Israa MS AL-Kadmy, Department of Biology, College of Science, AL-Mustansiryiah University, Baghdad-Iraq. Email: [email protected] 1. Definition and Chemical Structure Biopolymer is a term commonly used for polymers which are synthesized by living organisms [1]. Biopolymers originate from natural sources and are biologically renewable, biodegradable and biocompatible. Chitin and chitosan are the biopolymers that have received much research interests due to their numerous potential applications in agriculture, food in- dustry, biomedicine, paper making and textile industry.
    [Show full text]
  • Study of Actinobacteria and Their Secondary Metabolites from Various Habitats in Indonesia and Deep-Sea of the North Atlantic Ocean
    Study of Actinobacteria and their Secondary Metabolites from Various Habitats in Indonesia and Deep-Sea of the North Atlantic Ocean Von der Fakultät für Lebenswissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) genehmigte D i s s e r t a t i o n von Chandra Risdian aus Jakarta / Indonesien 1. Referent: Professor Dr. Michael Steinert 2. Referent: Privatdozent Dr. Joachim M. Wink eingereicht am: 18.12.2019 mündliche Prüfung (Disputation) am: 04.03.2020 Druckjahr 2020 ii Vorveröffentlichungen der Dissertation Teilergebnisse aus dieser Arbeit wurden mit Genehmigung der Fakultät für Lebenswissenschaften, vertreten durch den Mentor der Arbeit, in folgenden Beiträgen vorab veröffentlicht: Publikationen Risdian C, Primahana G, Mozef T, Dewi RT, Ratnakomala S, Lisdiyanti P, and Wink J. Screening of antimicrobial producing Actinobacteria from Enggano Island, Indonesia. AIP Conf Proc 2024(1):020039 (2018). Risdian C, Mozef T, and Wink J. Biosynthesis of polyketides in Streptomyces. Microorganisms 7(5):124 (2019) Posterbeiträge Risdian C, Mozef T, Dewi RT, Primahana G, Lisdiyanti P, Ratnakomala S, Sudarman E, Steinert M, and Wink J. Isolation, characterization, and screening of antibiotic producing Streptomyces spp. collected from soil of Enggano Island, Indonesia. The 7th HIPS Symposium, Saarbrücken, Germany (2017). Risdian C, Ratnakomala S, Lisdiyanti P, Mozef T, and Wink J. Multilocus sequence analysis of Streptomyces sp. SHP 1-2 and related species for phylogenetic and taxonomic studies. The HIPS Symposium, Saarbrücken, Germany (2019). iii Acknowledgements Acknowledgements First and foremost I would like to express my deep gratitude to my mentor PD Dr.
    [Show full text]
  • Effect of Sulfonylurea Tribenuron Methyl Herbicide on Soil
    b r a z i l i a n j o u r n a l o f m i c r o b i o l o g y 4 9 (2 0 1 8) 79–86 ht tp://www.bjmicrobiol.com.br/ Environmental Microbiology Effect of sulfonylurea tribenuron methyl herbicide on soil Actinobacteria growth and characterization of resistant strains a,b,∗ a,c d f e Kounouz Rachedi , Ferial Zermane , Radja Tir , Fatima Ayache , Robert Duran , e e e a,c Béatrice Lauga , Solange Karama , Maryse Simon , Abderrahmane Boulahrouf a Université Frères Mentouri, Faculté des Sciences de la Nature et de la Vie, Laboratoire de Génie Microbiologique et Applications, Constantine, Algeria b Université Frères Mentouri, Institut de la Nutrition, de l’Alimentation et des Technologies Agro-Alimentaires (INATAA), Constantine, Algeria c Université Frères Mentouri, Faculté des Sciences de la Nature et de la Vie, Département de Microbiologie, Constantine, Algeria d Université Frères Mentouri, Faculté des Sciences de la Nature et de la Vie, Laboratoire de Biologie Moléculaire et Cellulaire, Constantine, Algeria e Université de Pau et des Pays de l’Adour, Unité Mixte de Recherche 5254, Equipe Environnement et Microbiologie, Pau, France f Université Frères Mentouri, Constantine 1, Algeria a r t i c l e i n f o a b s t r a c t Article history: Repeated application of pesticides disturbs microbial communities and cause dysfunctions ® Received 28 October 2016 on soil biological processes. Granstar 75 DF is one of the most used sulfonylurea herbi- Accepted 6 May 2017 cides on cereal crops; it contains 75% of tribenuron-methyl.
    [Show full text]
  • Isolation and Characterization of Aerobic Actinomycetes with Probiotic Properties in Nile Tilapia
    Journal of Applied Pharmaceutical Science Vol. 10(09), pp 040-049, September, 2020 Available online at http://www.japsonline.com DOI: 10.7324/JAPS.2020.10905 ISSN 2231-3354 Isolation and characterization of aerobic actinomycetes with probiotic properties in Nile tilapia Jirayut Euanorasetr1,2*, Varissara Chotboonprasit1,2, Wacharaporn Ngoennamchok1,2, Sutassa Thongprathueang1,2, Archiraya Promprateep1,2, Suppakit Taweesaga1,2, Pongsan Chatsangjaroen1,2, Bungonsiri Intra3,4 1Department of Microbiology, Faculty of Science, King Mongkut’s University of Technology Thonburi, Khet Thung Khru, Bangkok 10140, Thailand 2Laboratory of biotechnological research for energy and bioactive compounds, Department of Microbiology, Faculty of Science, King Mongkut’s University of Technology Thonburi, Khet Thung Khru, Bangkok 10140, Thailand 3 Mahidol University-Osaka University: Collaborative Research Center for Bioscience and Biotechnology (MU-OU: CRC), Faculty of Science, Mahidol University, Bangkok 10400, Thailand 4Department of Biotechnology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand ARTICLE INFO ABSTRACT Received on: 20/04/2020 This study scoped the isolation of aerobic actinomycetes with probiotic properties against bacterial pathogens in Nile Accepted on: 23/06/2020 tilapia. Eleven rhizosphere soil samples were collected from the agricultural sites in three provinces (Chanthaburi, Available online: 05/09/2020 Nan, and Chachoengsao) of Thailand. A total of 157 actinomycete-like colonies were successfully isolated. The antibacterial
    [Show full text]
  • Phylogenetic Study of the Species Within the Family Streptomycetaceae
    Antonie van Leeuwenhoek DOI 10.1007/s10482-011-9656-0 ORIGINAL PAPER Phylogenetic study of the species within the family Streptomycetaceae D. P. Labeda • M. Goodfellow • R. Brown • A. C. Ward • B. Lanoot • M. Vanncanneyt • J. Swings • S.-B. Kim • Z. Liu • J. Chun • T. Tamura • A. Oguchi • T. Kikuchi • H. Kikuchi • T. Nishii • K. Tsuji • Y. Yamaguchi • A. Tase • M. Takahashi • T. Sakane • K. I. Suzuki • K. Hatano Received: 7 September 2011 / Accepted: 7 October 2011 Ó Springer Science+Business Media B.V. (outside the USA) 2011 Abstract Species of the genus Streptomyces, which any other microbial genus, resulting from academic constitute the vast majority of taxa within the family and industrial activities. The methods used for char- Streptomycetaceae, are a predominant component of acterization have evolved through several phases over the microbial population in soils throughout the world the years from those based largely on morphological and have been the subject of extensive isolation and observations, to subsequent classifications based on screening efforts over the years because they are a numerical taxonomic analyses of standardized sets of major source of commercially and medically impor- phenotypic characters and, most recently, to the use of tant secondary metabolites. Taxonomic characteriza- molecular phylogenetic analyses of gene sequences. tion of Streptomyces strains has been a challenge due The present phylogenetic study examines almost all to the large number of described species, greater than described species (615 taxa) within the family Strep- tomycetaceae based on 16S rRNA gene sequences Electronic supplementary material The online version and illustrates the species diversity within this family, of this article (doi:10.1007/s10482-011-9656-0) contains which is observed to contain 130 statistically supplementary material, which is available to authorized users.
    [Show full text]
  • Isolation and Characterization of Antagonistic Actinomycetes From
    Journal of Microbial & Biochemical Technology - Open Access JMBT/Vol.2 Issue 1 Research Article OPEN ACCESS Freely available online doi:10.4172/1948-5948.1000015 Isolation and Characterization of Antagonistic Actinomycetes from Marine Soil Lakshmipathy Deepika and Krishnan Kannabiran* Division of Biomolecules and Genetics, School of Biosciences and Technology, VIT University, Vellore- 632014, Tamil Nadu, India Abstract products from marine actinobacteria (Behal, 2003). Soil sample was collected from the coastal region of Tamil In this long run to combat drug resistant microorganisms, the Nadu with the aim of isolating actinobacteria and screen unexplored and less explored marine environments needs to be studied frequently. In the present study we have reported the them for antagonistic activity against common bacterial and isolation and identification of a marine actinobacteria from fungal pathogens. Serial dilution of the soil sample and sub- Ennore saltpan with moderate antibacterial, antifungal and sequent screening of the isolates obtained, resulted in the chitinolytic activity. identification of a potential strain VITDDK2 with signifi- cant activity against Klebsiella pneumoniae, Aspergillus Materials and Methods flavus and Aspergillus niger. In addition, the strain Location and sample collection VITDDK2 also possessed chitinolytic activity. Chemotaxo- Soil samples were aseptically collected in sterile polyethylene nomic analysis showed that the isolate VITDDK2 belongs bags from the Ennore saltpan (Lat. 13°.14’ N, Long. 80°.22’ E) to cell wall Type I. 16 S rRNA partial gene sequence and at a depth of 5-15 and stored in the refrigerator at 4°C for fur- phylogenetic analysis showed that the strain VITDDK2 ther study. Ennore coast is situated about 24 km north of Chennai shared 93% similarity with Streptomyces sp.
    [Show full text]
  • Mechanisms of Resistance to Β-Lactam Antibiotics in Streptomycetes Wedad
    Mechanisms of resistance to β-lactam antibiotics in streptomycetes Wedad Mohamed Omran Alkut A thesis submitted in partial fulfilment of the requirements of Liverpool John Moores University for the degree of Doctor of Philosophy April 2016 Contents DECLARATION ............................................................................................................... ix ACKNOWLEDGEMENTS ................................................................................................ x ABSTRACT ................................................................................................................... xi ABBREVIATIONS ............................................................................................................ 1 Literature review ............................................................................................................. 2 1. Streptomycetes Biology and Life cycle ...................................................................... 2 1.1 Characteristics of Streptomycetes ......................................................................... 2 1.2 The life cycle of Streptomyces .............................................................................. 3 1.3 Streptomyces coelicolor A3 (2) ............................................................................. 4 1.3.1 Actinorhodin (ACT) ........................................................................................... 5 1.3.2 Undecylprodigiosin (RED) ...............................................................................
    [Show full text]
  • Increasing Knowledge on the Mode of Action of Beneficial Microorganisms
    1 SYMBIOTIC AGRICULTURE: INCREASING KNOWLEDGE ON THE MODE OF ACTION OF BENEFICIAL MICROORGANISMS A thesis Submitted to the University of Modena and Reggio Emilia For the Degree of Doctor of Philosophy In the faculty of AGRI-FOOD SCIENCES, TECHNOLOGIES AND BIO- TECHNOLOGIES (Plant Pathology) Vurukonda Sai Shivakrishnaprasad Reggio Emilia, Italy, 2016-2019 2 Author’s Declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revision, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. 3 ABSTRACT Bacteria that are beneficial to plants are considered to be plant growth- promoting bacteria (PGPB) and can facilitate plant growth by a number of direct and indirect mechanisms. Non-pathogenic, soil microbes that occupy the rhizosphere can influence plant growth and induce changes in the plant’s physiological, chemical, metabolic, molecular activities, influencing plant-microbe interactions with abiotic and biotic stressors. Plants colonized by these microbes express unique plant phenotypes that show increased root and shoot mass, enhanced nutrient uptake, and stress mitigation. Additionally, the microbes may fix nitrogen and phosphate or produce siderophores for plant use. Among the plant-associated microbes, plant growth-promoting rhizobacteria (PGPR) are the most commonly used as inoculants for biofertilization. Plant growth-promoting rhizobacteria are non-pathogenic, free- living soil and root-inhabiting bacteria that colonize seeds, root tissue (endophytic/epiphytic), or the production of root exudates. In addition to these adaptations, PGPRs may utilize other mechanisms to facilitate plant growth including IAA synthesis, siderophore production, phosphate solubilization activity, ammonia production, and antifungal and antibacterial compounds production.
    [Show full text]
  • Actinomycetes from Neglected Areas, Iranian Soil, Their Taxonomy, and Secondary Metabolites
    Actinomycetes from neglected areas, Iranian soil, their taxonomy, and secondary metabolites Von der Fakultät für Lebenswissenschaften der Technischen Universität Carolo-Wilhelmina zu Braunschweig zur Erlangung des Grades einer Doktorin der Naturwissenschaften (Dr. rer. nat.) genehmigte D i s s e r t a t i o n von Shadi Khodamoradi aus Tabriz / Iran 1. Referent: Professor Dr. Michael Steinert 2. Referent: Privatdozent Dr. Joachim Wink eingereicht am: 09.02.2021 mündliche Prüfung (Disputation) am: 16.04.2021 Druckjahr 2021 ii Vorveröffentlichungen der Dissertation Teilergebnisse aus dieser Arbeit wurden mit Genehmigung der Fakultät für Lebenswissenschaften, vertreten durch den Mentor der Arbeit, in folgenden Beiträgen vorab veröffentlicht: Publikationen Khodamoradi S, Stadler M, Wink J, Surup F. Litoralimycins A and B, New Cytotoxic Thiopeptides from Streptomonospora sp. M2. Marine Drugs. 2020 Jun;18(6):280. Conference Talk Shadi Khodamoradi. Streptomonospora litoralis sp. nov., a halophilic actinomycetes with antibacterial activity from beach sands. 11th International PhD Symposium, Braunschweig, Germany (2018) Posterbeiträge Shadi Khodamoradi, Richard L. Hahnke, Frank Surup, Manfred Rohde, Michael Steinert, Marc Stadler, Joachim Wink. Isolation of a new Streptomonospora-species producing a new peptide antibiotic. The HIPS Symposium, Saarbrücken, Germany (2019). Shadi Khodamoradi. Isolation of new Streptomyces sp. producing the new antibacterial compound from the soil sample collected from Iran/ Tehran/ Alborz Mountain HZI. 12th International PhD Symposium, Braunschweig, Germany (2019) Shadi Khodamoradi. Isolation, characterization, and Antagonistic Properties of novel species of halophilic Streptomonospora.10th International PhD Symposium, Braunschweig, Germany (2017) iii Acknowledgements First of all, I want to give my sincere gratitude to my principal supervisor PD Dr. Joachim Wink for giving me the chance to explore the wonderful science and sharing his knowledge with me.
    [Show full text]
  • Plant Growth Promoting and Biocontrol Activity of Streptomyces Spp. As Endophytes
    International Journal of Molecular Sciences Review Plant Growth Promoting and Biocontrol Activity of Streptomyces spp. as Endophytes Sai Shiva Krishna Prasad Vurukonda *, Davide Giovanardi and Emilio Stefani * ID Department of Life Sciences, University of Modena and Reggio Emilia, via Amendola 2, 42122 Reggio Emilia, Italy; [email protected] * Correspondence: [email protected] (S.S.K.P.V.); [email protected] (E.S.); Tel.: +39-052-252-2062 (S.S.K.P.V.); +39-052-252-2013 (E.S.) Received: 18 February 2018; Accepted: 16 March 2018; Published: 22 March 2018 Abstract: There has been many recent studies on the use of microbial antagonists to control diseases incited by soilborne and airborne plant pathogenic bacteria and fungi, in an attempt to replace existing methods of chemical control and avoid extensive use of fungicides, which often lead to resistance in plant pathogens. In agriculture, plant growth-promoting and biocontrol microorganisms have emerged as safe alternatives to chemical pesticides. Streptomyces spp. and their metabolites may have great potential as excellent agents for controlling various fungal and bacterial phytopathogens. Streptomycetes belong to the rhizosoil microbial communities and are efficient colonizers of plant tissues, from roots to the aerial parts. They are active producers of antibiotics and volatile organic compounds, both in soil and in planta, and this feature is helpful for identifying active antagonists of plant pathogens and can be used in several cropping systems as biocontrol agents. Additionally, their ability to promote plant growth has been demonstrated in a number of crops, thus inspiring the wide application of streptomycetes as biofertilizers to increase plant productivity.
    [Show full text]
  • Chemical and Taxonomic Investigation of Indonesian Soil
    Chemical and Taxonomic Investigation of Indonesian Soil-dwelling Bacteria Dissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Eberhard Karls Universität Tübingen zur Erlangung des Grades eines Doktors der Naturwissenschaften (Dr. rer. nat.) vorgelegt von Saefuddin Aziz aus Purwokerto/Indonesien Tübingen 2021 Gedruckt mit Genehmigung der Mathematisch-Naturwissenschaftlichen Fakultät der Eberhard Karls Universität Tübingen. Tag der mündlichen Qualifikation: 20.05.2021 Dekan: Prof. Dr. Thilo Stehle 1. Berichterstatter: Prof. Dr. Harald Groß 2. Berichterstatter: PD Dr. Bertolt Gust Declaration I, Saefuddin Aziz declare that this thesis is an original report of my research, has been written by myself and has not been submitted for any previous degree. The experimental work is almost entirely my own work; the collaborative contributions have been indicated clearly and acknowledged. Due references have been provided on all supporting literatures and resources. Parts of this work have been published in Aziz, S., Mast, Y., Wohlleben, W., & Gross, H. (2018). Draft genome sequence of the pristinamycin-producing strain Streptomyces sp. SW4, isolated from soil in Nusa Kambangan, Indonesia. Microbiology resource announcements, 7(7). Tübingen, 29.03.2021 i Zusammenfassung Ziel des Projekts war es, taxonomisch neuartige bakterielle Stämme aus dem Biodiversitäts- Brennpunkt Indonesien zu isolieren und hieraus neue chemische Verbindungen zu isolieren. Zu diesem Zweck wurden 25 Stämme gesammelt und auf antimikrobielle Eigenschaften hin untersucht. Daraus resultierend wurden zunächst fünf und im späteren Verlauf dann nur noch ausschließlich die beiden Stämme Streptomyces sp. SW4 und Pseudomonas aeruginosa SW5 priorisiert. Während der Stamm SW5 nur bekannte Naturstoffe produzierte und eine bereits bekannte Spezies darstellte, erwies sich der Stamm SW4 im Rahmen von polyphasischen taxonomischen Untersuchungen als völlig neuartige Spezies.
    [Show full text]
  • 1.0 Introduction Actinobacteria Are Filamentous, Branching Bacteria That
    1.0 Introduction Actinobacteria are filamentous, branching bacteria that are widely distributed in nature. They are mainly found in soil, where they play a major role in the decomposition of organic matter. Actinobacteria may form a substrate mycelium only, or both aerial and substrate mycelia, or an aerial mycelium only. The hyphae are mostly about one micron or less in diameter. In some species, the cells are acid-fast. Although some species are holocarpic, eucarpic members may show highly complex mycelial structures with conidia and sporangia. Motility, when observed, is due to flagella. Conidia and sporangiospores may be variously arranged or variously structured with surface hairs, spines or ridges (Lechevalier and Pine, 1989; Locci, 1989). Actinobacteria is a diverse group of filamentous Gram positive bacteria. They are prokaryotes having high G+C content (more than 55%) in their DNA, with extremely various metabolic possibilities. The metabolic diversity of the actinobacteria family is due to their extremely large genome, which has hundreds of transcription factors that control gene expression, allowing them to respond to specific needs (Goshi et al., 2002). The majority of the actinobacteria are free living, saprophytic bacteria found widely distributed in soil, water and colonizing plants. Their population forms an important component of the soil microflora. Around 70-90% of the actinobacteria in virgin and cultivated soils are Streptomyces species (Alexander, 1961). The demand for new antibiotics continues to grow due to the rapid spread of antibiotic-resistant pathogens causing life-threatening infections. Although 1 considerable progress is being made within the fields of chemical synthesis and engineered biosynthesis of antifungal compounds, tropical nature still remains the richest and the most versatile source for new antibiotics (Bredholt et al., 2008).
    [Show full text]