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Tomasch J, Kopejtka K, Bílý T, Gardiner AT, Gardian Z, Shivaramu S, Koblížek M, Kaftan D. A photoheterotrophic bacterium from Iceland has adapted its photosynthetic machinery to the long days of polar summer. mSystems 2024; 9:e0131123. [PMID: 38376261 PMCID: PMC10949492 DOI: 10.1128/msystems.01311-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Accepted: 01/26/2024] [Indexed: 02/21/2024] Open
Abstract
During their long evolution, anoxygenic phototrophic bacteria have inhabited a wide variety of natural habitats and developed specific strategies to cope with the challenges of any particular environment. Expression, assembly, and safe operation of the photosynthetic apparatus must be regulated to prevent reactive oxygen species generation under illumination in the presence of oxygen. Here, we report on the photoheterotrophic Sediminicoccus sp. strain KRV36, which was isolated from a cold stream in north-western Iceland, 30 km south of the Arctic Circle. In contrast to most aerobic anoxygenic phototrophs, which stop pigment synthesis when illuminated, strain KRV36 maintained its bacteriochlorophyll synthesis even under continuous light. Its cells also contained between 100 and 180 chromatophores, each accommodating photosynthetic complexes that exhibit an unusually large carotenoid absorption spectrum. The expression of photosynthesis genes in dark-adapted cells was transiently downregulated in the first 2 hours exposed to light but recovered to the initial level within 24 hours. An excess of membrane-bound carotenoids as well as high, constitutive expression of oxidative stress response genes provided the required potential for scavenging reactive oxygen species, safeguarding bacteriochlorophyll synthesis and photosystem assembly. The unique cellular architecture and an unusual gene expression pattern represent a specific adaptation that allows the maintenance of anoxygenic phototrophy under arctic conditions characterized by long summer days with relatively low irradiance.IMPORTANCEThe photoheterotrophic bacterium Sediminicoccus sp. KRV36 was isolated from a cold stream in Iceland. It expresses its photosynthesis genes, synthesizes bacteriochlorophyll, and assembles functional photosynthetic complexes under continuous light in the presence of oxygen. Unraveling the molecular basis of this ability, which is exceptional among aerobic anoxygenic phototrophic species, will help to understand the evolution of bacterial photosynthesis in response to changing environmental conditions. It might also open new possibilities for genetic engineering of biotechnologically relevant phototrophs, with the aim of increasing photosynthetic activity and their tolerance to reactive oxygen species.
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Affiliation(s)
- Jürgen Tomasch
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - Karel Kopejtka
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - Tomáš Bílý
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Alastair T. Gardiner
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - Zdenko Gardian
- Institute of Parasitology, Biology Centre, Czech Academy of Sciences, České Budějovice, Czechia
| | - Sahana Shivaramu
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - Michal Koblížek
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
| | - David Kaftan
- Laboratory of Anoxygenic Phototrophs, Institute of Microbiology of the Czech Academy of Sciences, Třeboň, Czechia
- Department Chemistry, Faculty of Science, University of South Bohemia, České Budějovice, Czechia
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Madigan MT, Bender KS, Sanguedolce SA, Parenteau MN, Mayer MH, Kimura Y, Wang-Otomo ZY, Sattley WM. Genomic basis for the unique phenotype of the alkaliphilic purple nonsulfur bacterium Rhodobaca bogoriensis. Extremophiles 2023; 27:19. [PMID: 37481751 DOI: 10.1007/s00792-023-01304-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 07/14/2023] [Indexed: 07/25/2023]
Abstract
Although several species of purple sulfur bacteria inhabit soda lakes, Rhodobaca bogoriensis is the first purple nonsulfur bacterium cultured from such highly alkaline environments. Rhodobaca bogoriensis strain LBB1T was isolated from Lake Bogoria, a soda lake in the African Rift Valley. The phenotype of Rhodobaca bogoriensis is unique among purple bacteria; the organism is alkaliphilic but not halophilic, produces carotenoids absent from other purple nonsulfur bacteria, and is unable to grow autotrophically or fix molecular nitrogen. Here we analyze the draft genome sequence of Rhodobaca bogoriensis to gain further insight into the biology of this extremophilic purple bacterium. The strain LBB1T genome consists of 3.91 Mbp with no plasmids. The genome sequence supports the defining characteristics of strain LBB1T, including its (1) production of a light-harvesting 1-reaction center (LH1-RC) complex but lack of a peripheral (LH2) complex, (2) ability to synthesize unusual carotenoids, (3) capacity for both phototrophic (anoxic/light) and chemotrophic (oxic/dark) energy metabolisms, (4) utilization of a wide variety of organic compounds (including acetate in the absence of a glyoxylate cycle), (5) ability to oxidize both sulfide and thiosulfate despite lacking the capacity for autotrophic growth, and (6) absence of a functional nitrogen-fixation system for diazotrophic growth. The assortment of properties in Rhodobaca bogoriensis has no precedent among phototrophic purple bacteria, and the results are discussed in relation to the organism's soda lake habitat and evolutionary history.
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Affiliation(s)
- Michael T Madigan
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Kelly S Bender
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Sophia A Sanguedolce
- School of Biological Sciences, Southern Illinois University, Carbondale, IL, 62901, USA
| | - Mary N Parenteau
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Marisa H Mayer
- Exobiology Branch, NASA Ames Research Center, Moffett Field, CA, 94035, USA
| | - Yukihiro Kimura
- Department of Agrobioscience, Kobe University, Kobe, 657-8501, Japan
| | | | - W Matthew Sattley
- Division of Natural Sciences, Indiana Wesleyan University, Marion, IN, 46953, USA.
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3
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Trutschel LR, Kruger BR, Sackett JD, Chadwick GL, Rowe AR. Determining resident microbial community members and their correlations with geochemistry in a serpentinizing spring. Front Microbiol 2023; 14:1182497. [PMID: 37396382 PMCID: PMC10308030 DOI: 10.3389/fmicb.2023.1182497] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 05/24/2023] [Indexed: 07/04/2023] Open
Abstract
Terrestrial serpentinizing systems allow us insight into the realm of alkaliphilic microbial communities driven by geology in a way that is frequently more accessible than their deep subsurface or marine counterparts. However, these systems are also marked by geochemical and microbial community variation due to the interactions of serpentinized fluids with host geology and the surface environment. To separate the transient from the endemic microbes in a hyperalkaline environment, we assessed the Ney Springs terrestrial serpentinizing system microbial community and geochemistry at six time points over the span of a year. Using 16S rRNA gene surveys we observed 93 amplicon sequence variants (ASVs) that were found at every sampling event. This is compared to ~17,000 transient ASVs that were detected only once across the six sampling events. Of the resident community members, 16 of these ASVs were regularly greater than 1% of the community during every sampling period. Additionally, many of these core taxa experienced statistically significant changes in relative abundance with time. Variation in the abundance of some core populations correlated with geochemical variation. For example, members of the Tindallia group, showed a positive correlation with variation in levels of ammonia at the spring. Investigating the metagenome assembled genomes of these microbes revealed evidence of the potential for ammonia generation via Stickland reactions within Tindallia. This observation offers new insight into the origin of high ammonia concentrations (>70 mg/L) seen at this site. Similarly, the abundance of putative sulfur-oxidizing microbes like Thiomicrospira, Halomonas, and a Rhodobacteraceae species could be linked to changes observed in sulfur-oxidation intermediates like tetrathionate and thiosulfate. While these data supports the influence of core microbial community members on a hyperalkaline spring's geochemistry, there is also evidence that subsurface processes affect geochemistry and may impact community dynamics as well. Though the physiology and ecology of these astrobiologically relevant ecosystems are still being uncovered, this work helps identify a stable microbial community that impacts spring geochemistry in ways not previously observed in serpentinizing ecosystems.
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Affiliation(s)
- Leah R. Trutschel
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Brittany R. Kruger
- Division of Hydrologic Sciences, Desert Research Institute, Las Vegas, Las Vegas, NV, United States
| | - Joshua D. Sackett
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
| | - Grayson L. Chadwick
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA, United States
| | - Annette R. Rowe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, United States
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4
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Tanabe Y, Yamaguchi H, Yoshida M, Kai A, Okazaki Y. Characterization of a bloom-associated alphaproteobacterial lineage, 'Candidatus Phycosocius': insights into freshwater algal-bacterial interactions. ISME COMMUNICATIONS 2023; 3:20. [PMID: 36906708 PMCID: PMC10008586 DOI: 10.1038/s43705-023-00228-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Revised: 02/23/2023] [Accepted: 03/01/2023] [Indexed: 03/13/2023]
Abstract
Marine bacterial lineages associated with algal blooms, such as the Roseobacter clade, have been well characterized in ecological and genomic contexts, yet such lineages have rarely been explored in freshwater blooms. This study performed phenotypic and genomic analyses of an alphaproteobacterial lineage 'Candidatus Phycosocius' (denoted the CaP clade), one of the few lineages ubiquitously associated with freshwater algal blooms, and described a novel species: 'Ca. Phycosocius spiralis.' Phylogenomic analyses indicated that the CaP clade is a deeply branching lineage in the Caulobacterales. Pangenome analyses revealed characteristic features of the CaP clade: aerobic anoxygenic photosynthesis and essential vitamin B auxotrophy. Genome size varies widely among members of the CaP clade (2.5-3.7 Mb), likely a result of independent genome reductions at each lineage. This includes a loss of tight adherence pilus genes (tad) in 'Ca. P. spiralis' that may reflect its adoption of a unique spiral cell shape and corkscrew-like burrowing activity at the algal surface. Notably, quorum sensing (QS) proteins showed incongruent phylogenies, suggesting that horizontal transfers of QS genes and QS-involved interactions with specific algal partners might drive CaP clade diversification. This study elucidates the ecophysiology and evolution of proteobacteria associated with freshwater algal blooms.
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Affiliation(s)
- Yuuhiko Tanabe
- Biodiversity Division, National Institute for Environmental Studies, Ibaraki, 305-8506, Japan.
- Algae Biomass and Energy System R&D Center, University of Tsukuba, Ibaraki, 305-8572, Japan.
| | - Haruyo Yamaguchi
- Biodiversity Division, National Institute for Environmental Studies, Ibaraki, 305-8506, Japan
| | - Masaki Yoshida
- Algae Biomass and Energy System R&D Center, University of Tsukuba, Ibaraki, 305-8572, Japan
| | - Atsushi Kai
- Algae Biomass and Energy System R&D Center, University of Tsukuba, Ibaraki, 305-8572, Japan
| | - Yusuke Okazaki
- Institute for Chemical Research, Kyoto University, Kyoto, 611-0011, Japan
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Isolation and Genomics of Futiania mangrovii gen. nov., sp. nov., a Rare and Metabolically Versatile Member in the Class Alphaproteobacteria. Microbiol Spectr 2023; 11:e0411022. [PMID: 36541777 PMCID: PMC9927469 DOI: 10.1128/spectrum.04110-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Mangrove microorganisms are a major part of the coastal ecosystem and are directly associated with nutrient cycling. Despite their ecological significance, the collection of culturable mangrove microbes is limited due to difficulties in isolation and cultivation. Here, we report the isolation and genome sequence of strain FT118T, the first cultured representative of a previously uncultivated order UBA8317 within Alphaproteobacteria, based on the combined results of 16S rRNA gene similarity, phylogenomic, and average amino acid identity analyses. We propose Futianiales ord. nov. and Futianiaceae fam. nov. with Futiania as the type genus, and FT118T represents the type species with the name Futiania mangrovii gen. nov, sp. nov. The 16S rRNA gene sequence comparison reveals that this novel order is a rare member but has a ubiquitous distribution across various habitats worldwide, which is corroborated by the experimental confirmation that this isolate can physiologically adapt to a wide range of oxygen levels, temperatures, pH and salinity levels. Biochemical characterization, genomic annotation, and metatranscriptomic analysis of FT118T demonstrate that it is metabolically versatile and active in situ. Genomic analysis reveals adaptive features of Futianiales to fluctuating mangrove environments, including the presence of high- and low-affinity terminal oxidases, N-type ATPase, and the genomic capability of producing various compatible solutes and polyhydroxybutyrate, which possibly allow for the persistence of this novel order across various habitats. Collectively, these results expand the current culture collection of mangrove microorganisms, providing genomic insights of how this novel taxon adapts to fluctuating environments and the culture reference to unravel possible microbe-environment interactions. IMPORTANCE The rare biosphere constitutes an essential part of the microbial community and may drive nutrient cycling and other geochemical processes. However, the difficulty in microbial isolation and cultivation has hampered our understanding of the physiology and ecology of uncultured rare lineages. In this study, we successfully isolated a novel alphaproteobacterium, designated as FT118T, and performed a combination of phenotypic, phylogenetic, and phylogenomic analyses, confirming that this isolate represents the first cultured member of a previously uncultivated order UBA8317 within Alphaproteobacteria. It is a rare species with a ubiquitous distribution across different habitats. Genomic and metatranscriptomic analyses demonstrate that it is metabolically versatile and active in situ, suggesting its potential role in nutrient cycling despite being scarce. This work not only expands the current phylogeny of isolated Alphaproteobacteria but also provides genomic and culture reference to unravel microbial adaptation strategies in mangrove sediments and possible microbe-environment interactions.
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Villena‐Alemany C, Mujakić I, Porcal P, Koblížek M, Piwosz K. Diversity dynamics of aerobic anoxygenic phototrophic bacteria in a freshwater lake. ENVIRONMENTAL MICROBIOLOGY REPORTS 2023; 15:60-71. [PMID: 36507772 PMCID: PMC10103773 DOI: 10.1111/1758-2229.13131] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 09/19/2022] [Indexed: 05/20/2023]
Abstract
Aerobic anoxygenic photoheterotrophic (AAP) bacteria represent a functional group of prokaryotic organisms that harvests light energy using bacteriochlorophyll-containing photosynthetic reaction centers. They represent an active and rapidly growing component of freshwater bacterioplankton, with the highest numbers observed usually in summer. Species diversity of freshwater AAP bacteria has been studied before in lakes, but its seasonal dynamics remain unknown. In this report, we analysed temporal changes in the composition of the phototrophic community in an oligo-mesotrophic freshwater lake using amplicon sequencing of the pufM marker gene. The AAP community was dominated by phototrophic Gammaproteobacteria and Alphaproteobacteria, with smaller contribution of phototrophic Chloroflexota and Gemmatimonadota. Phototrophic Eremiobacteriota or members of Myxococcota were not detected. Interestingly, some AAP taxa, such as Limnohabitans, Rhodoferax, Rhodobacterales or Rhizobiales, were permanently present over the sampling period, while others, such as Sphingomonadales, Rhodospirillales or Caulobacterales appeared only transiently. The environmental factors that best explain the seasonal changes in AAP community were temperature, concentrations of oxygen and dissolved organic matter.
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Affiliation(s)
- Cristian Villena‐Alemany
- Laboratory of Anoxygenic PhototrophsInstitute of Microbiology of the Czech Academy of SciencesTřeboňCzechia
- Department of Ecosystem Biology, Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzechia
| | - Izabela Mujakić
- Laboratory of Anoxygenic PhototrophsInstitute of Microbiology of the Czech Academy of SciencesTřeboňCzechia
- Department of Ecosystem Biology, Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzechia
| | - Petr Porcal
- Department of Ecosystem Biology, Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzechia
- Department of Hydrochemistry and Ecosystem Modelling, Biology Centre of the Czech Academy of SciencesInstitute of HydrobiologyČeské BudějoviceCzechia
| | - Michal Koblížek
- Laboratory of Anoxygenic PhototrophsInstitute of Microbiology of the Czech Academy of SciencesTřeboňCzechia
- Department of Ecosystem Biology, Faculty of ScienceUniversity of South BohemiaČeské BudějoviceCzechia
| | - Kasia Piwosz
- Department of Fisheries Oceanography and Marine EcologyNational Marine Fisheries Research InstituteGdyniaPoland
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7
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Ma Y, You F, Parry D, Urban A, Huang L. Adaptive growth and acidogenic fermentation performance of haloalkaliphilic bacterial communities enriched from biofilms colonising strongly alkaline and saline bauxite residue. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 856:159131. [PMID: 36183768 DOI: 10.1016/j.scitotenv.2022.159131] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2022] [Revised: 09/25/2022] [Accepted: 09/26/2022] [Indexed: 06/16/2023]
Abstract
The present study aimed to characterise the adaptive growth and acidogenic fermentation performance of haloalkaliphilic bacteria sourced from field biofilms colonising seawater-treated bauxite residue, under moderate and extremely alkaline pH conditions (8.5 to 10.8) and coupled saline (EC ≈ 50 mS/cm) conditions. The haloalkaliphilic bacterial communities demonstrated strong adaptiveness to the increasing pH from 8.5 to 10.8. The dominant groups were Exiguobacterales and Bacillales at pH 8.5 and 10, but Lactobacillales and Bacillales at pH 10.8. The exposure to pH 10.8 initially delayed bacterial growth in the first 24 h, but which rapidly recovered to a peak rate at 48 h similar to that in the pH 10 treatment. Correspondingly, lactic acid concentration at pH 10.8 rapidly rose to as high as >2000 mg/L at 48 h. Bacterial growth and organic acid production were positively related to carbohydrate supply. Overall, these bacterial groups fermented glucose to produce mainly lactic acid (>80 %) and other acids (such as acetic acid, formic acid, and succinic acid), leading to 0.5-2.0 units of pH reduction, despite the strong buffering capacity in the culture solution. The bacteria could up-regulate their phosphatase activity to mineralise the organic P in the basal nutrient broth, but increasing soluble phosphate-P at a 1:10 of glucose-C was beneficial. The biofilm-sourced bacteria communities contained redundant fermentative haloalkaliphilic groups which were adaptive to strongly alkaline pH and saline conditions.
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Affiliation(s)
- Yuanying Ma
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Fang You
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, Queensland 4072, Australia.
| | - David Parry
- Rio Tinto, Brisbane, Queensland 4000, Australia
| | - Anja Urban
- Queensland Alumina Limited, Gladstone, Queensland 4680, Australia
| | - Longbin Huang
- Centre for Mined Land Rehabilitation, Sustainable Minerals Institute, The University of Queensland, Brisbane, Queensland 4072, Australia
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Trutschel LR, Chadwick GL, Kruger B, Blank JG, Brazelton WJ, Dart ER, Rowe AR. Investigation of microbial metabolisms in an extremely high pH marine-like terrestrial serpentinizing system: Ney Springs. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 836:155492. [PMID: 35476949 DOI: 10.1016/j.scitotenv.2022.155492] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 04/06/2022] [Accepted: 04/20/2022] [Indexed: 06/14/2023]
Abstract
Ney Springs, a continental serpentinizing spring in northern California, has an exceptionally high reported pH (12.4) for a naturally occurring water source. With high conductivity fluids, it is geochemically more akin to marine serpentinizing systems than other terrestrial locations. Our geochemical analyses also revealed high sulfide concentrations (544 mg/L) and methane emissions (83% volume gas content) relative to other serpentinizing systems. Thermodynamic calculations were used to investigate the potential for substrates resulting from serpentinization to fuel microbial life, and were found to support the energetic feasibility of sulfate reduction, anaerobic methane oxidation, denitrification, and anaerobic sulfide oxidation within this system. Assessment of the microbial community via 16S rRNA taxonomic gene surveys and metagenome sequencing revealed a community composition dominated by poorly characterized members of the Izemoplasmatales and Clostridiales. The genomes of these dominant taxa point to a fermentative lifestyle, though other highly complete (>90%) metagenome assembled genomes support the potential for organisms to perform sulfate reduction, sulfur disproportionation and/or sulfur oxidation (aerobic and anaerobic). Two chemolithoheterotrophs identified in the metagenome, a Halomonas sp. and a Rhodobacteraceae sp., were isolated and shown to oxidize thiosulfate and were capable of growth in conditions up to pH 12.4. Despite being characteristic products of serpentinization reactions, little evidence was seen for hydrogen and methane utilization in the Ney Springs microbial community. Hydrogen is not highly abundant and could be consumed prior to reaching the spring community. Other metabolic strategies may be outcompeted by more energetically favorable heterotrophic or fermentation reactions, or even inhibited by other compounds in the spring such as ammonia. The unique geochemistry of Ney Springs provides an opportunity to study how local geology interacts with serpentinized fluids, while its microbial community can better inform us of the metabolic strategies employed in hyperalkaline environments.
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Affiliation(s)
- Leah R Trutschel
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA
| | - Grayson L Chadwick
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | | | - Jennifer G Blank
- Blue Marble Space Institute of Science, Livermore, CA, USA; NASA Ames Research Center in Silicon Valley, Moffett Field, CA, USA
| | | | - Emily R Dart
- School of Biological Sciences, University of Utah, Salt Lake City, UT, USA
| | - Annette R Rowe
- Department of Biological Sciences, University of Cincinnati, Cincinnati, OH, USA.
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Yang H, Hu C. Soil Chemistry and Nutrients Influence the Distribution of Aerobic Anoxygenic Phototrophic Bacteria and Eukaryotic Phototrophic Microorganisms of Physical Soil Crusts at Different Elevations on the Tibetan Plateau. MICROBIAL ECOLOGY 2022; 83:100-113. [PMID: 33733304 DOI: 10.1007/s00248-021-01734-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Accepted: 03/10/2021] [Indexed: 06/12/2023]
Abstract
Photosynthetic microorganisms are widely distributed in the soil and play an important role in plant-free soil crusts. However, the distribution and environmental drivers of phototrophic microbial communities in physical soil crusts, where the abundance of cyanobacteria is low, are scarcely understood. Here, we performed high-throughput sequencing of pufM and 18S rRNA genes in soil crusts at different elevations on the Tibetan Plateau and used the data combined with environmental variables to analyze the diversity and structure of phototrophic microbial communities. We found that the dominant taxa of aerobic anoxygenic phototrophic bacteria (AAPB) and eukaryotic phototrophic microorganisms (EPM) were shown to shift with elevation. The phototrophic microbial diversity showed a single-peak pattern, with the lowest diversity of AAPB and highest diversity of EPM at middle elevations. Moreover, the elevation and soil property determined the phototrophic microbial community. Soil salts, especially Cl-, were the most important for AAPB. Likewise, soil nutrients, especially carbon, were the most important for EPM. The relationship between high-abundance taxa and environmental variables showed that Rhizobiales was significantly negatively correlated with salt ions and positively correlated with chlorophyll. Rhodobacterales showed the strongest and significant positive associations with Cl-. Chlorophyceae and Bacillariophyceae were positively correlated with CO32-. These results indicated that salinity and soil nutrients affected the diversity and structure of microbial communities. This study contributes to our understanding of the diversity, composition, and structure of photosynthetic microorganisms in physical soil crusts and helps in developing new approaches for controlling desertification and salinization and improving the desert ecological environment.
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Affiliation(s)
- Haijian Yang
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China
| | - Chunxiang Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, China.
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10
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Improvement of wastewater treatment capacity using the microalga Scenedesmus sp. and membrane bioreactors. ALGAL RES 2021. [DOI: 10.1016/j.algal.2021.102516] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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11
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Illuminating key microbial players and metabolic processes involved in the remineralization of particulate organic carbon in the ocean's twilight zone by metaproteomics. Appl Environ Microbiol 2021; 87:e0098621. [PMID: 34319792 DOI: 10.1128/aem.00986-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The twilight zone (from the base of the euphotic zone to the depth of 1000 m) is the major area of particulate organic carbon (POC) remineralization in the ocean, and heterotrophic microbes contribute to more than 70% of the estimated remineralization. However, little is known about the microbial community and metabolic activity directly associated with POC remineralization in this chronically understudied realm. Here, we characterized the microbial community proteomes of POCs collected from the twilight zone of three contrasting sites in the Northwest Pacific Ocean using a metaproteomic approach. The particle-attached bacteria from Alteromonadales, Rhodobacterales, and Enterobacteriales were the primary POC remineralizers. Hydrolytic enzymes, including proteases and hydrolases, that degrade proteinaceous components and polysaccharides, the main constituents of POC, were abundant and taxonomically associated with these bacterial groups. Furthermore, identification of diverse species-specific transporters and metabolic enzymes implied niche specialization for nutrient acquisition among these bacterial groups. Temperature was the main environmental factor driven the active bacterial groups and metabolic processes, and Enterobacteriales replaced Alteromonadales as the predominant group under low temperature. This study provides insight into the key bacteria and metabolic processes involved in POC remineralization, and niche complementarity and species substitution among bacterial groups are critical for efficient POC remineralization in the twilight zone. IMPORTANCE The Ocean's twilight zone is a critical zone where more than 70% of the sinking particulate organic carbon (POC) are remineralized. Therefore, the twilight zone determines the size of biological carbon storage in the ocean, and regulates the global climate. Prokaryotes are major players that govern remineralization of POC in this region. However, knowledge of microbial community structure and metabolic activity is still lacking. This study unveiled microbial communities and metabolic activities of POCs collected from the twilight zone of three contrasting environments in the Northwest Pacific Ocean using a metaproteomic approach. Alteromonadales, Rhodobacterales and Enterobacteriales were the major remineralizers of POC. They excreted diverse species-specific hydrolytic enzymes to split POC to solubilized POC or dissolved organic carbon. Temperature played a crucial role in regulating the community composition and metabolism. Furthermore, niche complementarity or species substitution among bacterial groups guaranteed the efficient remineralization of POC in the twilight zone.
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Kopejtka K, Tomasch J, Zeng Y, Selyanin V, Dachev M, Piwosz K, Tichý M, Bína D, Gardian Z, Bunk B, Brinkmann H, Geffers R, Sommaruga R, Koblížek M. Simultaneous Presence of Bacteriochlorophyll and Xanthorhodopsin Genes in a Freshwater Bacterium. mSystems 2020; 5:e01044-20. [PMID: 33361324 PMCID: PMC7762795 DOI: 10.1128/msystems.01044-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Accepted: 11/30/2020] [Indexed: 01/01/2023] Open
Abstract
Photoheterotrophic bacteria represent an important part of aquatic microbial communities. There exist two fundamentally different light-harvesting systems: bacteriochlorophyll-containing reaction centers or rhodopsins. Here, we report a photoheterotrophic Sphingomonas strain isolated from an oligotrophic lake, which contains complete sets of genes for both rhodopsin-based and bacteriochlorophyll-based phototrophy. Interestingly, the identified genes were not expressed when cultured in liquid organic media. Using reverse transcription quantitative PCR (RT-qPCR), RNA sequencing, and bacteriochlorophyll a quantification, we document that bacteriochlorophyll synthesis was repressed by high concentrations of glucose or galactose in the medium. Coactivation of photosynthesis genes together with genes for TonB-dependent transporters suggests the utilization of light energy for nutrient import. The photosynthetic units were formed by ring-shaped light-harvesting complex 1 and reaction centers with bacteriochlorophyll a and spirilloxanthin as the main light-harvesting pigments. The identified rhodopsin gene belonged to the xanthorhodopsin family, but it lacks salinixanthin antenna. In contrast to bacteriochlorophyll, the expression of xanthorhodopsin remained minimal under all experimental conditions tested. Since the gene was found in the same operon as a histidine kinase, we propose that it might serve as a light sensor. Our results document that photoheterotrophic Sphingomonas bacteria use the energy of light under carbon-limited conditions, while under carbon-replete conditions, they cover all their metabolic needs through oxidative phosphorylation.IMPORTANCE Phototrophic organisms are key components of many natural environments. There exist two main phototrophic groups: species that collect light energy using various kinds of (bacterio)chlorophylls and species that utilize rhodopsins. Here, we present a freshwater bacterium Sphingomonas sp. strain AAP5 which contains genes for both light-harvesting systems. We show that bacteriochlorophyll-based reaction centers are repressed by light and/or glucose. On the other hand, the rhodopsin gene was not expressed significantly under any of the experimental conditions. This may indicate that rhodopsin in Sphingomonas may have other functions not linked to bioenergetics.
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Affiliation(s)
- Karel Kopejtka
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Jürgen Tomasch
- Research Group Microbial Communication, Technical University of Braunschweig, Braunschweig, Germany
| | - Yonghui Zeng
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
- Department of Environmental Science, Aarhus University, Aarhus, Denmark
| | - Vadim Selyanin
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Marko Dachev
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Kasia Piwosz
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - Martin Tichý
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
| | - David Bína
- Institute of Plant Molecular Biology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Institute of Parasitology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Zdenko Gardian
- Institute of Plant Molecular Biology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Institute of Parasitology, Biology Center of the Czech Academy of Sciences, České Budějovice, Czechia
- Faculty of Science, University of South Bohemia, České Budějovice, Czechia
| | - Boyke Bunk
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Henner Brinkmann
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Robert Geffers
- Research Group Genome Analytics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ruben Sommaruga
- Laboratory of Aquatic Photobiology and Plankton Ecology, Department of Ecology, University of Innsbruck, Innsbruck, Austria
| | - Michal Koblížek
- Center Algatech, Institute of Microbiology of the Czech Academy of Science, Třeboň, Czechia
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13
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Year-long assessment of a pilot-scale thin-layer reactor for microalgae wastewater treatment. Variation in the microalgae-bacteria consortium and the impact of environmental conditions. ALGAL RES 2020. [DOI: 10.1016/j.algal.2020.101983] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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14
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Gardiner AT, Nguyen-Phan TC, Cogdell RJ. A comparative look at structural variation among RC-LH1 'Core' complexes present in anoxygenic phototrophic bacteria. PHOTOSYNTHESIS RESEARCH 2020; 145:83-96. [PMID: 32430765 PMCID: PMC7423801 DOI: 10.1007/s11120-020-00758-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Accepted: 05/10/2020] [Indexed: 05/30/2023]
Abstract
All purple photosynthetic bacteria contain RC-LH1 'Core' complexes. The structure of this complex from Rhodobacter sphaeroides, Rhodopseudomonas palustris and Thermochromatium tepidum has been solved using X-ray crystallography. Recently, the application of single particle cryo-EM has revolutionised structural biology and the structure of the RC-LH1 'Core' complex from Blastochloris viridis has been solved using this technique, as well as the complex from the non-purple Chloroflexi species, Roseiflexus castenholzii. It is apparent that these structures are variations on a theme, although with a greater degree of structural diversity within them than previously thought. Furthermore, it has recently been discovered that the only phototrophic representative from the phylum Gemmatimonadetes, Gemmatimonas phototrophica, also contains a RC-LH1 'Core' complex. At present only a low-resolution EM-projection map exists but this shows that the Gemmatimonas phototrophica complex contains a double LH1 ring. This short review compares these different structures and looks at the functional significance of these variations from two main standpoints: energy transfer and quinone exchange.
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Affiliation(s)
- Alastair T Gardiner
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK.
- Laboratory of Anoxygenic Phototrophs, Centre Algatech, Institute of Microbiology of the Czech Academy of Sciences, Novohradska 237, 379 01, Třeboň, Czech Republic.
| | - Tu C Nguyen-Phan
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
| | - Richard J Cogdell
- Institute of Molecular, Cellular and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8QQ, UK
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Matturro B, Mascolo G, Rossetti S. Microbiome changes and oxidative capability of an anaerobic PCB dechlorinating enrichment culture after oxygen exposure. N Biotechnol 2020; 56:96-102. [DOI: 10.1016/j.nbt.2019.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 12/18/2019] [Accepted: 12/22/2019] [Indexed: 12/16/2022]
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16
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Arif S, Reitner J, Hoppert M. Composition, Diversity and Functional Analysis of the Modern Microbiome of the Middle Triassic Cava Superiore Beds (Monte San Giorgio, Switzerland). Sci Rep 2019; 9:20394. [PMID: 31892704 PMCID: PMC6938485 DOI: 10.1038/s41598-019-55955-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Accepted: 12/03/2019] [Indexed: 11/25/2022] Open
Abstract
Organic-rich laminated shales and limestones from the Monte San Giorgio (Lugano Prealps, Switzerland) are known as famous fossil lagerstätten for excellently preserved fossils from the Middle Triassic Period. The various bituminous shales from Monte San Giorgio are thermally immature and rich in diverse organic compounds, which provide unique substrates for active soil microbial communities. We selected the Cava superior beds of the Acqua del Ghiffo site for this study. To investigate its microbial structure and diversity, contig assembly, Operational Taxonomic Units (OTUs) clustering, and rarefaction analysis were performed for bacterial 16S rDNA preparations from bituminous and non-bituminous limestone strata with the MetaAmp pipeline. Principal coordinates analysis shows that the microbial communities from the bituminous strata differ significantly from limestone samples (P < 0.05 Unifrac weighted). Moreover, metagenomic tools could also be used effectively to analyze the microbial communities shift during enrichment in specific growth media. In the nutrient-rich media, one or few taxa, mainly Proteobacteria and Firmicutes, were enriched which led to the drastic diversity loss while oligotrophic media could enrich many taxa simultaneously and sustain the richness and diversity of the inoculum. Piphillin, METAGENassist and MicrobiomeAnalyst pipeline also predicted that the Monte San Giorgio bituminous shales and oligotrophic enriched microbiomes degrade complex polycyclic aromatic hydrocarbons.
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Affiliation(s)
- Sania Arif
- Institute of Microbiology & Genetics, Department of General Microbiology, Georg-August-Universität Göttingen, Göttingen, Germany.
| | - Joachim Reitner
- Geosciences Centre, Department of Geobiology, Georg-August-Universität Göttingen, Göttingen, Germany
| | - Michael Hoppert
- Institute of Microbiology & Genetics, Department of General Microbiology, Georg-August-Universität Göttingen, Göttingen, Germany
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Vavourakis CD, Mehrshad M, Balkema C, van Hall R, Andrei AŞ, Ghai R, Sorokin DY, Muyzer G. Metagenomes and metatranscriptomes shed new light on the microbial-mediated sulfur cycle in a Siberian soda lake. BMC Biol 2019; 17:69. [PMID: 31438955 PMCID: PMC6704655 DOI: 10.1186/s12915-019-0688-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/09/2019] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND The planetary sulfur cycle is a complex web of chemical reactions that can be microbial-mediated or can occur spontaneously in the environment, depending on the temperature and pH. Inorganic sulfur compounds can serve as energy sources for specialized prokaryotes and are important substrates for microbial growth in general. Here, we investigate dissimilatory sulfur cycling in the brine and sediments of a southwestern Siberian soda lake characterized by an extremely high pH and salinity, combining meta-omics analyses of its uniquely adapted highly diverse prokaryote communities with biogeochemical profiling to identify key microbial players and expand our understanding of sulfur cycling under haloalkaline conditions. RESULTS Peak microbial activity was found in the top 4 cm of the sediments, a layer with a steep drop in oxygen concentration and redox potential. The majority of sulfur was present as sulfate or iron sulfide. Thiosulfate was readily oxidized by microbes in the presence of oxygen, but oxidation was partially inhibited by light. We obtained 1032 metagenome-assembled genomes, including novel population genomes of characterized colorless sulfur-oxidizing bacteria (SOB), anoxygenic purple sulfur bacteria, heterotrophic SOB, and highly active lithoautotrophic sulfate reducers. Surprisingly, we discovered the potential for nitrogen fixation in a new genus of colorless SOB, carbon fixation in a new species of phototrophic Gemmatimonadetes, and elemental sulfur/sulfite reduction in the "Candidatus Woesearchaeota." Polysulfide/thiosulfate and tetrathionate reductases were actively transcribed by various (facultative) anaerobes. CONCLUSIONS The recovery of over 200 genomes that encoded enzymes capable of catalyzing key reactions in the inorganic sulfur cycle indicates complete cycling between sulfate and sulfide at moderately hypersaline and extreme alkaline conditions. Our results suggest that more taxonomic groups are involved in sulfur dissimilation than previously assumed.
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Affiliation(s)
- Charlotte D Vavourakis
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Maliheh Mehrshad
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Cherel Balkema
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands
| | - Rutger van Hall
- Department of Ecosystem & Landscape Dynamics, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, the Netherlands
| | - Adrian-Ştefan Andrei
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Rohit Ghai
- Department of Aquatic Microbial Ecology, Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic, České Budějovice, Czech Republic
| | - Dimitry Y Sorokin
- Winogradsky Institute of Microbiology, Research Centre of Biotechnology, Russian Academy of Sciences, Moscow, Russian Federation
- Department of Biotechnology, Environmental Biotechnology, Delft University of Technology, Delft, the Netherlands
| | - Gerard Muyzer
- Microbial Systems Ecology, Department of Freshwater and Marine Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94240, 1090 GE, Amsterdam, the Netherlands.
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Kopejtka K, Lin Y, Jakubovičová M, Koblížek M, Tomasch J. Clustered Core- and Pan-Genome Content on Rhodobacteraceae Chromosomes. Genome Biol Evol 2019; 11:2208-2217. [PMID: 31273387 PMCID: PMC6699656 DOI: 10.1093/gbe/evz138] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/29/2019] [Indexed: 12/18/2022] Open
Abstract
In Bacteria, chromosome replication starts at a single origin of replication and proceeds on both replichores. Due to its asymmetric nature, replication influences chromosome structure and gene organization, mutation rate, and expression. To date, little is known about the distribution of highly conserved genes over the bacterial chromosome. Here, we used a set of 101 fully sequenced Rhodobacteraceae representatives to analyze the relationship between conservation of genes within this family and their distance from the origin of replication. Twenty-two of the analyzed species had core genes clustered significantly closer to the origin of replication with representatives of the genus Celeribacter being the most apparent example. Interestingly, there were also eight species with the opposite organization. In particular, Rhodobaca barguzinensis and Loktanella vestfoldensis showed a significant increase of core genes with distance from the origin of replication. The uneven distribution of low-conserved regions is in particular pronounced for genomes in which the halves of one replichore differ in their conserved gene content. Phage integration and horizontal gene transfer partially explain the scattered nature of Rhodobacteraceae genomes. Our findings lay the foundation for a better understanding of bacterial genome evolution and the role of replication therein.
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Affiliation(s)
- Karel Kopejtka
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Yan Lin
- Department of Physics, School of Science, Tianjin University, China
- SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, Tianjin, China
| | - Markéta Jakubovičová
- Faculty of Information Technology, Czech Technical University in Prague, Czech Republic
| | - Michal Koblížek
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
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Kopejtka K, Tomasch J, Bunk B, Spröer C, Wagner-Döbler I, Koblížek M. The complete genome sequence of Rhodobaca barguzinensis alga05 (DSM 19920) documents its adaptation for life in soda lakes. Extremophiles 2018; 22:839-849. [PMID: 30022245 DOI: 10.1007/s00792-018-1041-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 07/09/2018] [Indexed: 12/19/2022]
Abstract
Soda lakes, with their high salinity and high pH, pose a very challenging environment for life. Microorganisms living in these harsh conditions have had to adapt their physiology and gene inventory. Therefore, we analyzed the complete genome of the haloalkaliphilic photoheterotrophic bacterium Rhodobaca barguzinensis strain alga05. It consists of a 3,899,419 bp circular chromosome with 3624 predicted coding sequences. In contrast to most of Rhodobacterales, this strain lacks any extrachromosomal elements. To identify the genes responsible for adaptation to high pH, we compared the gene inventory in the alga05 genome with genomes of 17 reference strains belonging to order Rhodobacterales. We found that all haloalkaliphilic strains contain the mrpB gene coding for the B subunit of the MRP Na+/H+ antiporter, while this gene is absent in all non-alkaliphilic strains, which indicates its importance for adaptation to high pH. Further analysis showed that alga05 requires organic carbon sources for growth, but it also contains genes encoding the ethylmalonyl-CoA pathway for CO2 fixation. Remarkable is the genetic potential to utilize organophosphorus compounds as a source of phosphorus. In summary, its genetic inventory indicates a large flexibility of the alga05 metabolism, which is advantageous in rapidly changing environmental conditions in soda lakes.
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Affiliation(s)
- Karel Kopejtka
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic.,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - Jürgen Tomasch
- Department of Molecular Bacteriology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Boyke Bunk
- Department of Microbial Ecology and Diversity Research, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Cathrin Spröer
- Department of Microbial Ecology and Diversity Research, Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Irene Wagner-Döbler
- Institute of Microbiology, Braunschweig University of Technology, Braunschweig, Germany
| | - Michal Koblížek
- Laboratory of Anoxygenic Phototrophs, Center Algatech, Institute of Microbiology CAS, Třeboň, Czech Republic. .,Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic.
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Horizontal operon transfer, plasmids, and the evolution of photosynthesis in Rhodobacteraceae. ISME JOURNAL 2018; 12:1994-2010. [PMID: 29795276 PMCID: PMC6052148 DOI: 10.1038/s41396-018-0150-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/23/2018] [Accepted: 04/26/2018] [Indexed: 01/24/2023]
Abstract
The capacity for anoxygenic photosynthesis is scattered throughout the phylogeny of the Proteobacteria. Their photosynthesis genes are typically located in a so-called photosynthesis gene cluster (PGC). It is unclear (i) whether phototrophy is an ancestral trait that was frequently lost or (ii) whether it was acquired later by horizontal gene transfer. We investigated the evolution of phototrophy in 105 genome-sequenced Rhodobacteraceae and provide the first unequivocal evidence for the horizontal transfer of the PGC. The 33 concatenated core genes of the PGC formed a robust phylogenetic tree and the comparison with single-gene trees demonstrated the dominance of joint evolution. The PGC tree is, however, largely incongruent with the species tree and at least seven transfers of the PGC are required to reconcile both phylogenies. The origin of a derived branch containing the PGC of the model organism Rhodobacter capsulatus correlates with a diagnostic gene replacement of pufC by pufX. The PGC is located on plasmids in six of the analyzed genomes and its DnaA-like replication module was discovered at a conserved central position of the PGC. A scenario of plasmid-borne horizontal transfer of the PGC and its reintegration into the chromosome could explain the current distribution of phototrophy in Rhodobacteraceae.
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Thiel V, Tank M, Bryant DA. Diversity of Chlorophototrophic Bacteria Revealed in the Omics Era. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:21-49. [PMID: 29505738 DOI: 10.1146/annurev-arplant-042817-040500] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Because of recent advances in omics methodologies, knowledge of chlorophototrophy (i.e., chlorophyll-based phototrophy) in bacteria has rapidly increased. Chlorophototrophs currently are known to occur in seven bacterial phyla: Cyanobacteria, Proteobacteria, Chlorobi, Chloroflexi, Firmicutes, Acidobacteria, and Gemmatimonadetes. Other organisms that can produce chlorophylls and photochemical reaction centers may still be undiscovered. Here we summarize the current status of the taxonomy and phylogeny of chlorophototrophic bacteria as revealed by genomic methods. In specific cases, we briefly describe important ecophysiological and metabolic insights that have been gained from the application of genomic methods to these bacteria. In the 20 years since the completion of the Synechocystis sp. PCC 6803 genome in 1996, approximately 1,100 genomes have been sequenced, which represents nearly the complete diversity of known chlorophototrophic bacteria. These data are leading to new insights into many important processes, including photosynthesis, nitrogen and carbon fixation, cellular differentiation and development, symbiosis, and ecosystem functionality.
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Affiliation(s)
- Vera Thiel
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Marcus Tank
- Department of Biological Sciences, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397, Japan; ,
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania 16802, USA;
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA
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Martin WF, Bryant DA, Beatty JT. A physiological perspective on the origin and evolution of photosynthesis. FEMS Microbiol Rev 2018; 42:205-231. [PMID: 29177446 PMCID: PMC5972617 DOI: 10.1093/femsre/fux056] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 11/20/2017] [Indexed: 12/22/2022] Open
Abstract
The origin and early evolution of photosynthesis are reviewed from an ecophysiological perspective. Earth's first ecosystems were chemotrophic, fueled by geological H2 at hydrothermal vents and, required flavin-based electron bifurcation to reduce ferredoxin for CO2 fixation. Chlorophyll-based phototrophy (chlorophototrophy) allowed autotrophs to generate reduced ferredoxin without electron bifurcation, providing them access to reductants other than H2. Because high-intensity, short-wavelength electromagnetic radiation at Earth's surface would have been damaging for the first chlorophyll (Chl)-containing cells, photosynthesis probably arose at hydrothermal vents under low-intensity, long-wavelength geothermal light. The first photochemically active pigments were possibly Zn-tetrapyrroles. We suggest that (i) after the evolution of red-absorbing Chl-like pigments, the first light-driven electron transport chains reduced ferredoxin via a type-1 reaction center (RC) progenitor with electrons from H2S; (ii) photothioautotrophy, first with one RC and then with two, was the bridge between H2-dependent chemolithoautotrophy and water-splitting photosynthesis; (iii) photothiotrophy sustained primary production in the photic zone of Archean oceans; (iv) photosynthesis arose in an anoxygenic cyanobacterial progenitor; (v) Chl a is the ancestral Chl; and (vi), anoxygenic chlorophototrophic lineages characterized so far acquired, by horizontal gene transfer, RCs and Chl biosynthesis with or without autotrophy, from the architects of chlorophototrophy-the cyanobacterial lineage.
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Affiliation(s)
- William F Martin
- Institute for Molecular Evolution, University of Düsseldorf, D-40225 Düsseldorf, Germany
| | - Donald A Bryant
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
- Department of Chemistry and Biochemistry, Montana State University, Bozeman, MT 59717, USA
| | - J Thomas Beatty
- Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, V6T 1Z3, Canada
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