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Uroz S, Geisler O, Fauchery L, Lami R, Rodrigues AMS, Morin E, Leveau JHJ, Oger P. Genomic and transcriptomic characterization of the Collimonas quorum sensing genes and regulon. FEMS Microbiol Ecol 2022; 98:6679101. [PMID: 36040340 DOI: 10.1093/femsec/fiac100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 07/13/2022] [Accepted: 08/26/2022] [Indexed: 01/21/2023] Open
Abstract
Collimonads are well-adapted to nutrient-poor environments. They are known to hydrolyse chitin, produce antifungal metabolites, weather minerals, and are effective biocontrol agents protecting plants from fungal diseases. The production of N-acyl homoserine lactones (AHLs) was suggested to be a conserved trait of collimonads, but little is known about the genes that underlie this production or the genes that are controlled by AHLs. To improve our understanding of the role of AHLs in the ecology of collimonads, we carried out transcriptomic analyses, combined with chemical and functional assays, on strain Collimonas pratensis PMB3(1). The main AHLs produced by this strain were identified as 3-hydroxy-hexa- and octa-noyl-homoserine lactone. Genome analysis permitted to identify putative genes coding for the autoinducer synthase (colI) and cognate transcriptional regulator (colR). The ability to produce AHLs was lost in ΔcolI and ΔcolR mutants. Functional assays revealed that the two mutants metabolized glucose, formate, oxalate, and leucine better than the wild-type (WT) strain. Transcriptome sequencing analyses revealed an up-regulation of different metabolic pathways and of motility in the QS-mutants compared to the WT strain. Overall, our results provide insights into the role of the AHL-dependent regulation system of Collimonas in environment colonization, metabolism readjustment, and microbial interactions.
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Affiliation(s)
- Stephane Uroz
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France.,INRAE, UR1138 "Biogéochimie des écosystèmes forestiers", F-54280 Champenoux, France
| | - Océane Geisler
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Laure Fauchery
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Raphaël Lami
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM, USR3579), Fédération de Recherche FR3724, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France
| | - Alice M S Rodrigues
- Sorbonne Université, CNRS, Laboratoire de Biodiversité et Biotechnologies Microbiennes (LBBM, USR3579), Fédération de Recherche FR3724, Observatoire Océanologique, 66650 Banyuls-sur-Mer, France
| | - Emmanuelle Morin
- Université de Lorraine, INRAE, UMR1136 "Interactions Arbres-Microorganismes", F-54280 Champenoux, France
| | - Johan H J Leveau
- Department of Plant Pathology, University of California - Davis, Davis, CA 95616, United States
| | - Philippe Oger
- Université Lyon, INSA de Lyon, CNRS UMR 5240, F-69622 Villeurbanne, France
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Optimizing viability and yield and improving stability of Gram-negative, non-spore forming plant-beneficial bacteria encapsulated by spray-drying. Bioprocess Biosyst Eng 2021; 44:2289-2301. [PMID: 34184107 DOI: 10.1007/s00449-021-02604-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 06/17/2021] [Indexed: 10/21/2022]
Abstract
This study investigates methods to commercialize safer alternatives to chemical pesticides that pose risks to human safety and the environment. Spray-drying encapsulation of the plant-protective, antifungal bacterium Collimonas arenae Cal35 in in situ cross-linked alginate microcapsules (CLAMs) was optimized to minimize losses during spray-drying and maximize yield of spray-dried powder. Only inlet temperature significantly affected survival during spray-drying, while inlet temperature, spray rate, and alginate concentration significantly affected yield of spray-dried powder. Lowering inlet temperature to 95 °C provided the greatest survival during spray-drying, while increasing inlet temperature and lowering spray rate and alginate concentration produced the highest yield. Without the CLAMs formulation, Cal35 did not survive spray-drying. When Cal35 was encapsulated in CLAMs in the presence of modified starch, shelf survival was extended to 3 weeks in a low oxygen, low humidity storage environment. Cal35 retained its antifungal activity throughout spray-drying and shelf storage, supporting its potential use as a formulated biofungicide product.
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Repeated Exposure of Aspergillus niger Spores to the Antifungal Bacterium Collimonas fungivorans Ter331 Selects for Delayed Spore Germination. Appl Environ Microbiol 2021; 87:e0023321. [PMID: 33811027 DOI: 10.1128/aem.00233-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The bacterial strain Collimonas fungivorans Ter331 (CfTer331) inhibits mycelial growth and spore germination in Aspergillus niger N402 (AnN402). The mechanisms underlying this antagonistic bacterial-fungal interaction have been extensively studied, but knowledge on the long-term outcome of this interaction is currently lacking. Here, we used experimental evolution to explore the dynamics of fungal adaptation to recurrent exposure to CfTer331. Specifically, five single-spore isolates (SSIs) of AnN402 were evolved under three selection scenarios in liquid culture, i.e., (i) in the presence of CfTer331 for 80 growth cycles, (ii) in the absence of the bacterium for 80 cycles, and (iii) in the presence of CfTer331 for 40 cycles and then in its absence for 40 cycles. The evolved SSI lineages were then evaluated for phenotypic changes from the founder fungal strain, such as germinability with or without CfTer331. The analysis showed that recurrent exposure to CfTer331 selected for fungal lineages with reduced germinability and slower germination, even in the absence of CfTer331. In contrast, when AnN402 evolved in the absence of the bacteria, lineages with increased germinability and faster germination were favored. SSIs that were first evolved in the presence of CfTer331 and then in its absence showed intermediate phenotypes but overall were more similar to SSIs that evolved in the absence of CfTer331 for 80 cycles. This suggests that traits acquired from exposure to CfTer331 were reversible upon removal of the selection pressure. Overall, our study provides insights into the effects on fungi from the long-term coculture with bacteria. IMPORTANCE The use of antagonistic bacteria for managing fungal diseases is becoming increasingly popular, and thus there is a need to understand the implications of their long-term use against fungi. Most efforts have so far focused on characterizing the antifungal properties and mode of action of the bacterial antagonists, but the possible outcomes of the persisting interaction between antagonistic bacteria and fungi are not well understood. In this study, we used experimental evolution in order to explore the evolutionary aspects of an antagonistic bacterial-fungal interaction, using the antifungal bacterium Collimonas fungivorans and the fungus Aspergillus niger as a model system. We show that evolution in the presence or absence of the bacteria selects for fungal lineages with opposing and conditionally beneficial traits, such as slow and fast spore germination, respectively. Overall, our studies reveal that fungal responses to biotic factors related to antagonism could be to some extent predictable and reversible.
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Mosquera S, Stergiopoulos I, Leveau JHJ. Interruption of Aspergillus niger spore germination by the bacterially produced secondary metabolite collimomycin. ENVIRONMENTAL MICROBIOLOGY REPORTS 2020; 12:306-313. [PMID: 32162788 DOI: 10.1111/1758-2229.12833] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Revised: 03/02/2020] [Accepted: 03/03/2020] [Indexed: 06/10/2023]
Abstract
Collimonas fungivorans Ter331 (CfTer331) is a soil bacterium that produces collimomycin, a secondary metabolite that inhibits the vegetative growth of fungi. Here we show that CfTer331 can also interfere with fungal spore germination and that collimomycin biosynthesis is required for this activity. More specifically, in co-cultures of Aspergillus niger N402 (AnN402) co-nidiospores with CfTer331, the rate of transition from the isotropic to polarized stage of the germination process was reduced and the relatively few AnN402 conidiospores that completed the germination process were less likely to survive than those that were arrested in the isotropic phase. By contrast, a collimomycin-deficient mutant of CfTer331 had no effect on germination: in its presence, as in the absence or delayed presence of CfTer331, unhindered germination of conidiospores allowed rapid establishment of AnN402 mycelium and the subsequent acidification of the culture medium to the detriment of any bacteria present. However, when challenged early enough with CfTer331, the collimomycin-dependent arrest of the AnN402 germination process enabled CfTer331 to prevent AnN402 from forming mycelia and to gain dominance in the culture. We propose that the collimomycin-dependent arrest of spore germination represents an early intervention strategy used by CfTer331 to mitigate niche construction by fungi in nature.
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Affiliation(s)
- Sandra Mosquera
- Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA, 95616-8751
| | - Ioannis Stergiopoulos
- Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA, 95616-8751
| | - Johan H J Leveau
- Department of Plant Pathology, University of California Davis, One Shields Avenue, Davis, CA, 95616-8751
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Kai K, Sogame M, Sakurai F, Nasu N, Fujita M. Collimonins A–D, Unstable Polyynes with Antifungal or Pigmentation Activities from the Fungus-Feeding Bacterium Collimonas fungivorans Ter331. Org Lett 2018; 20:3536-3540. [DOI: 10.1021/acs.orglett.8b01311] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kenji Kai
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Mai Sogame
- Graduate School of Life and Environmental Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan
| | - Fumie Sakurai
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Norihiro Nasu
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Makoto Fujita
- Department of Applied Chemistry, Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
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Aslam M, Takahashi N, Matsubara K, Imanaka T, Kanai T, Atomi H. Identification of the glucosamine kinase in the chitinolytic pathway of Thermococcus kodakarensis. J Biosci Bioeng 2018; 125:320-326. [DOI: 10.1016/j.jbiosc.2017.10.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 10/07/2017] [Accepted: 10/10/2017] [Indexed: 01/13/2023]
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Song C, Schmidt R, de Jager V, Krzyzanowska D, Jongedijk E, Cankar K, Beekwilder J, van Veen A, de Boer W, van Veen JA, Garbeva P. Exploring the genomic traits of fungus-feeding bacterial genus Collimonas. BMC Genomics 2015; 16:1103. [PMID: 26704531 PMCID: PMC4690342 DOI: 10.1186/s12864-015-2289-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 12/11/2015] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND Collimonas is a genus belonging to the class of Betaproteobacteria and consists mostly of soil bacteria with the ability to exploit living fungi as food source (mycophagy). Collimonas strains differ in a range of activities, including swimming motility, quorum sensing, extracellular protease activity, siderophore production, and antimicrobial activities. RESULTS In order to reveal ecological traits possibly related to Collimonas lifestyle and secondary metabolites production, we performed a comparative genomics analysis based on whole-genome sequencing of six strains representing 3 recognized species. The analysis revealed that the core genome represents 43.1 to 52.7% of the genomes of the six individual strains. These include genes coding for extracellular enzymes (chitinase, peptidase, phospholipase), iron acquisition and type II secretion systems. In the variable genome, differences were found in genes coding for secondary metabolites (e.g. tripropeptin A and volatile terpenes), several unknown orphan polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS), nonribosomal peptide synthetase (NRPS) gene clusters, a new lipopeptide and type III and type VI secretion systems. Potential roles of the latter genes in the interaction with other organisms were investigated. Mutation of a gene involved in tripropeptin A biosynthesis strongly reduced the antibacterial activity against Staphylococcus aureus, while disruption of a gene involved in the biosynthesis of the new lipopeptide had a large effect on the antifungal/oomycetal activities. CONCLUSIONS Overall our results indicated that Collimonas genomes harbour many genes encoding for novel enzymes and secondary metabolites (including terpenes) important for interactions with other organisms and revealed genomic plasticity, which reflect the behaviour, antimicrobial activity and lifestylesof Collimonas spp.
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Affiliation(s)
- Chunxu Song
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Ruth Schmidt
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Victor de Jager
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Dorota Krzyzanowska
- Laboratory of Biological Plant Protection, Intercollegiate Faculty of Biotechnology UG&MUG, Kladki 24, Gdansk, 80-822, Poland.
| | - Esmer Jongedijk
- Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, Wageningen, 6708 PB, The Netherlands.
| | - Katarina Cankar
- Business Unit Bioscience, Plant Research International, Wageningen University and Research Centre, Wageningen, The Netherlands.
| | - Jules Beekwilder
- Business Unit Bioscience, Plant Research International, Wageningen University and Research Centre, Wageningen, The Netherlands.
| | - Anouk van Veen
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Wietse de Boer
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Johannes A van Veen
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
| | - Paolina Garbeva
- Netherlands Institute of Ecology, Department of Microbial Ecology, Droevendaalsesteeg 10, Wageningen, 6708 PB, The Netherlands.
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Abstract
We announce the finished genome sequence of soil forest isolate Collimonas arenae Cal35, which comprises a 5.6-Mbp chromosome and 41-kb plasmid. The Cal35 genome is the second one published for the bacterial genus Collimonas and represents the first opportunity for high-resolution comparison of genome content and synteny among collimonads.
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Fritsche K, van den Berg M, de Boer W, van Beek TA, Raaijmakers JM, van Veen JA, Leveau JHJ. Biosynthetic genes and activity spectrum of antifungal polyynes fromCollimonas fungivorans Ter331. Environ Microbiol 2014; 16:1334-45. [DOI: 10.1111/1462-2920.12440] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 01/16/2014] [Indexed: 01/13/2023]
Affiliation(s)
- Kathrin Fritsche
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
- BioDetection Systems b.v.; Amsterdam The Netherlands
| | - Marlies van den Berg
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
| | - Wietse de Boer
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
| | - Teris A. van Beek
- Laboratory of Organic Chemistry; Wageningen University; Wageningen The Netherlands
| | - Jos M. Raaijmakers
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
- Laboratory of Phytopathology; Wageningen University; Wageningen The Netherlands
| | - Johannes A. van Veen
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
- Institute of Biology; Leiden University; Leiden The Netherlands
| | - Johan H. J. Leveau
- Department of Microbial Ecology; Netherlands Institute of Ecology (NIOO-KNAW); Wageningen The Netherlands
- Department of Plant Pathology; University of California; Davis CA USA
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Cretoiu MS, Korthals GW, Visser JHM, van Elsas JD. Chitin amendment increases soil suppressiveness toward plant pathogens and modulates the actinobacterial and oxalobacteraceal communities in an experimental agricultural field. Appl Environ Microbiol 2013; 79:5291-301. [PMID: 23811512 PMCID: PMC3753968 DOI: 10.1128/aem.01361-13] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2013] [Accepted: 06/22/2013] [Indexed: 11/20/2022] Open
Abstract
A long-term experiment on the effect of chitin addition to soil on the suppression of soilborne pathogens was set up and monitored for 8 years in an experimental field, Vredepeel, The Netherlands. Chitinous matter obtained from shrimps was added to soil top layers on two different occasions, and the suppressiveness of soil toward Verticillium dahliae, as well as plant-pathogenic nematodes, was assessed, in addition to analyses of the abundances and community structures of members of the soil microbiota. The data revealed that chitin amendment had raised the suppressiveness of soil, in particular toward Verticillium dahliae, 9 months after the (second) treatment, extending to 2 years following treatment. Moreover, major effects of the added chitin on the soil microbial communities were detected. First, shifts in both the abundances and structures of the chitin-treated soil microbial communities, both of total soil bacteria and fungi, were found. In addition, the abundances and structures of soil actinobacteria and the Oxalobacteraceae were affected by chitin. At the functional gene level, the abundance of specific (family-18 glycoside hydrolase) chitinase genes carried by the soil bacteria also revealed upshifts as a result of the added chitin. The effects of chitin noted for the Oxalobacteraceae were specifically related to significant upshifts in the abundances of the species Duganella violaceinigra and Massilia plicata. These effects of chitin persisted over the time of the experiment.
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Affiliation(s)
- Mariana Silvia Cretoiu
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
| | - Gerard W. Korthals
- Applied Plant Research Institute, Wageningen University, Lelystad, The Netherlands
| | - Johnny H. M. Visser
- Applied Plant Research Institute, Wageningen University, Lelystad, The Netherlands
| | - Jan Dirk van Elsas
- Department of Microbial Ecology, Centre for Ecological and Evolutionary Studies, University of Groningen, Groningen, The Netherlands
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Mela F, Fritsche K, de Boer W, van den Berg M, van Veen JA, Maharaj NN, Leveau JHJ. Comparative genomics of bacteria from the genus Collimonas: linking (dis)similarities in gene content to phenotypic variation and conservation. ENVIRONMENTAL MICROBIOLOGY REPORTS 2012; 4:424-432. [PMID: 23760828 DOI: 10.1111/j.1758-2229.2012.00336.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Collimonas is a genus of soil bacteria comprising three recognized species: C. fungivorans, C. pratensis and C. arenae. Collimonads share the ability to degrade chitin (chitinolysis), feed on living fungal hyphae (mycophagy), and dissolve minerals (weathering), but vary in their inhibition of fungi (fungistasis). To better understand this phenotypic variability, we analysed the genomic content of four strains representing three Collimonas species (Ter14, Ter6, Ter91 and Ter10) by hybridization to a microarray based on reference strain C. fungivorans Ter331. The analysis revealed genes unique to strain Ter331 (e.g. those on the extrachromosomal element pTer331) and genes present in some but not all of the tested strains. Among the latter were several candidates that may contribute to fungistasis, including genes for the production and secretion of antifungals. We hypothesize that differential possession of these genes underlies the specialization of Collimonas strains towards different fungal hosts. We identified a set of 136 genes that were common in all tested Collimonas strains, but absent from the genomes of three other members of the family Oxalobacteraceae. Predicted products of these 'Collimonas core' genes include lytic, secreted enzymes such as chitinases, peptidases, nucleases and phosphatases with a putative role in mycophagy and weathering.
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Affiliation(s)
- F Mela
- Department of Microbial Ecology, Netherlands Institute of Ecology (NIOO-KNAW), Wageningen, the Netherlands Institute of Biology, Leiden University, Leiden, the Netherlands Department of Plant Pathology, University of California, Davis, CA 95616, USA
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Abstract
Chitinases, which can hydrolyze chitin, occur in a wide range of microorganisms including viruses, bacteria, and fungi. The derivatives of chitin are potentially useful in several areas such as food processing, medicines, and biological control in agriculture. Some bacteria can uptake and utilize chitin as carbon source by secreting chitinase. The chitin is degraded into chito-oligosaccharides [(GlcNAc)n] or N-acetylglucosamine (GlcNAc) by chitinases, and then the chitin derivatives are transferred into cells by specific transport systems of bacteria. The intracellular chitin derivatives activate or suppress the transcription of a series of chi genes and affect the amount of chitinase. The expression of chitinase genes are strictly regulated by various regulatory factors and responsive cis-acting elements. The present review will focus on the transport system and the regulation of chitinase genes expression in bacteria.
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De Luca G, Barakat M, Ortet P, Fochesato S, Jourlin-Castelli C, Ansaldi M, Py B, Fichant G, Coutinho PM, Voulhoux R, Bastien O, Maréchal E, Henrissat B, Quentin Y, Noirot P, Filloux A, Méjean V, DuBow MS, Barras F, Barbe V, Weissenbach J, Mihalcescu I, Verméglio A, Achouak W, Heulin T. The cyst-dividing bacterium Ramlibacter tataouinensis TTB310 genome reveals a well-stocked toolbox for adaptation to a desert environment. PLoS One 2011; 6:e23784. [PMID: 21912644 PMCID: PMC3164672 DOI: 10.1371/journal.pone.0023784] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2011] [Accepted: 07/25/2011] [Indexed: 11/22/2022] Open
Abstract
Ramlibacter tataouinensis TTB310(T) (strain TTB310), a betaproteobacterium isolated from a semi-arid region of South Tunisia (Tataouine), is characterized by the presence of both spherical and rod-shaped cells in pure culture. Cell division of strain TTB310 occurs by the binary fission of spherical "cyst-like" cells ("cyst-cyst" division). The rod-shaped cells formed at the periphery of a colony (consisting mainly of cysts) are highly motile and colonize a new environment, where they form a new colony by reversion to cyst-like cells. This unique cell cycle of strain TTB310, with desiccation tolerant cyst-like cells capable of division and desiccation sensitive motile rods capable of dissemination, appears to be a novel adaptation for life in a hot and dry desert environment. In order to gain insights into strain TTB310's underlying genetic repertoire and possible mechanisms responsible for its unusual lifestyle, the genome of strain TTB310 was completely sequenced and subsequently annotated. The complete genome consists of a single circular chromosome of 4,070,194 bp with an average G+C content of 70.0%, the highest among the Betaproteobacteria sequenced to date, with total of 3,899 predicted coding sequences covering 92% of the genome. We found that strain TTB310 has developed a highly complex network of two-component systems, which may utilize responses to light and perhaps a rudimentary circadian hourglass to anticipate water availability at the dew time in the middle/end of the desert winter nights and thus direct the growth window to cyclic water availability times. Other interesting features of the strain TTB310 genome that appear to be important for desiccation tolerance, including intermediary metabolism compounds such as trehalose or polyhydroxyalkanoate, and signal transduction pathways, are presented and discussed.
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Affiliation(s)
- Gilles De Luca
- CEA, Lab Ecol Microbienne Rhizosphere & Environm Extre, iBEB, DSV, Saint-Paul-lez-Durance, France.
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Leveau JHJ, Uroz S, de Boer W. The bacterial genusCollimonas: mycophagy, weathering and other adaptive solutions to life in oligotrophic soil environments. Environ Microbiol 2010; 12:281-92. [DOI: 10.1111/j.1462-2920.2009.02010.x] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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