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Rangamaran VR, Sankara Subramanian SH, Balachandran KRS, Gopal D. Vertical Microbial Profiling of Arabian Sea Oxygen Minimal Zone Reveals Complex Bacterial Communities and Distinct Functional Implications. MICROBIAL ECOLOGY 2023; 85:357-371. [PMID: 35195736 DOI: 10.1007/s00248-021-01952-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Arabian Sea harbours one of the largest oxygen minimal zones (OMZs) among the global oceans wherein biogeochemical cycles are regulated through dominant and complex microbial processes. The present study investigated the bacterial communities at various depths of the Arabian Sea OMZ using high-throughput sequencing of the v3-v4 hyper variable region of 16S rRNA gene. A total of 10 samples which included water samples from 8 different depths and 2 sediment samples were analyzed in this study. About 2.7 million sequences were obtained from all the samples. The sequence analysis revealed high bacterial diversity at deep waters and sediment samples and comparatively less species richness at the core OMZ depths. Number of OTUs ranged from 114 to 14441.Taxonomic assignments of the obtained OTUs showed dominant presence of Proteobacteria, Bacteriodetes, and Chloroflexi across all the samples. The identified OTUs were further affiliated to the phyla Marinimicrobia, Colwellia, Nitrospina, Tepidicaulis, Shewanella, Pseudoalteromonas, Woeseia at various depths along the water column. Correlation with abiotic factors suggested distinct variation in bacterial community composition with change in depth and dissolved oxygen (DO) levels. Predictive functional annotation based on bacterial phylotypes suggested presence of active nitrogen, sulphur, carbon, and methane metabolic cycles along the vertical transect of the studied region. Presence of nitrogen reduction bacterial group below the core OMZ depths may potentially provide insight into the expansion of OMZ region in Arabian Sea. Functional profiling further revealed presence of genes related to xenobiotic degradation in the water and sediment samples indicating a potential hotspot for bio-prospection.
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Affiliation(s)
- Vijaya Raghavan Rangamaran
- Marine Biotechnology Division, Ocean Science and Technology for Islands Group, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences (MoES), Government of India, Pallikaranai, Chennai, 600100, India.
| | - Sai H Sankara Subramanian
- Marine Biotechnology Division, Ocean Science and Technology for Islands Group, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences (MoES), Government of India, Pallikaranai, Chennai, 600100, India
| | - Karpaga Raja Sundari Balachandran
- Marine Biotechnology Division, Ocean Science and Technology for Islands Group, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences (MoES), Government of India, Pallikaranai, Chennai, 600100, India
| | - Dharani Gopal
- Marine Biotechnology Division, Ocean Science and Technology for Islands Group, National Institute of Ocean Technology (NIOT), Ministry of Earth Sciences (MoES), Government of India, Pallikaranai, Chennai, 600100, India.
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Takeuchi M, Yoshioka H. Acetate excretion by a methanotroph, Methylocaldum marinum S8, under aerobic conditions. Biosci Biotechnol Biochem 2021; 85:2326-2333. [PMID: 34459486 DOI: 10.1093/bbb/zbab150] [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: 06/29/2021] [Accepted: 08/25/2021] [Indexed: 11/14/2022]
Abstract
Methane-oxidizing bacteria (methanotrophs) often coexist with methylotrophs that utilize methanol excreted by methanotrophs. Recently, we found that a facultative methylotroph, Methyloceanibacter caenitepidi Gela4T, possibly utilizes acetate rather than methanol in the coculture with a methanotroph, Methylocaldum marinum S8. Here, we examined the effects of oxygen concentrations on growth of and acetate excretion by M. marinum S8 in pure culture and the coculture with M. caenitepidi Gela4T. M. marinum S8 excreted acetate during the exponential growth phase not only under microaerobic (O2 concentrations of 3.5%-6%) but also under aerobic (O2 concentrations of 20%-31%) conditions. RNA-Seq analyses of M. marinum S8 cells grown under aerobic conditions suggested that phosphoketolase and acetate kinase were candidate genes involved in acetate production. Nonmethylotrophic bacteria, Cupriavidus necator NBRC 102504, could grow when cocultured with M. marinum S8, also supporting the existence of methanol-independent cross-feeding from M. marinum S8 under aerobic conditions.
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Affiliation(s)
- Mio Takeuchi
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Midorigaoka, Ikeda, Osaka, Japan
| | - Hideyoshi Yoshioka
- Institute for Geo-resources and Environments, National Institute of Advanced Industrial Science and Technology (AIST), Higashi, Tsukuba, Ibaraki, Japan
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Konttinen O, Carmody J, Pathuri S, Anderson K, Zhou X, Reich N. Cell cycle regulated DNA methyltransferase: fluorescent tracking of a DNA strand-separation mechanism and identification of the responsible protein motif. Nucleic Acids Res 2020; 48:11589-11601. [PMID: 33053173 PMCID: PMC7672430 DOI: 10.1093/nar/gkaa844] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/10/2020] [Accepted: 09/23/2020] [Indexed: 12/23/2022] Open
Abstract
DNA adenine methylation by Caulobacter crescentus Cell Cycle Regulated Methyltransferase (CcrM) is an important epigenetic regulator of gene expression. The recent CcrM-DNA cocrystal structure shows the CcrM dimer disrupts four of the five base pairs of the (5'-GANTC-3') recognition site. We developed a fluorescence-based assay by which Pyrrolo-dC tracks the strand separation event. Placement of Pyrrolo-dC within the DNA recognition site results in a fluorescence increase when CcrM binds. Non-cognate sequences display little to no fluorescence changes, showing that strand separation is a specificity determinant. Conserved residues in the C-terminal segment interact with the phospho-sugar backbone of the non-target strand. Replacement of these residues with alanine results in decreased methylation activity and changes in strand separation. The DNA recognition mechanism appears to occur with the Type II M.HinfI DNA methyltransferase and an ortholog of CcrM, BabI, but not with DNA methyltransferases that lack the conserved C-terminal segment. The C-terminal segment is found broadly in N4/N6-adenine DNA methyltransferases, some of which are human pathogens, across three Proteobacteria classes, three other phyla and in Thermoplasma acidophilum, an Archaea. This Pyrrolo-dC strand separation assay should be useful for the study of other enzymes which likely rely on a strand separation mechanism.
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Affiliation(s)
- Olivia Konttinen
- Biomolecular Science and Engineering, University of California Santa Barbara, Santa Barbara, CA 93103, USA
| | - Jason Carmody
- Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93103, USA
| | - Sarath Pathuri
- Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93103, USA
| | - Kyle Anderson
- Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93103, USA
| | - Xiaofeng Zhou
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Chan Zuckerberg Biohub, San Francisco, CA 94158, USA
| | - Norbert Reich
- Biomolecular Science and Engineering, University of California Santa Barbara, Santa Barbara, CA 93103, USA
- Chemistry and Biochemistry, University of California Santa Barbara, Santa Barbara, CA 93103, USA
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Hördt A, López MG, Meier-Kolthoff JP, Schleuning M, Weinhold LM, Tindall BJ, Gronow S, Kyrpides NC, Woyke T, Göker M. Analysis of 1,000+ Type-Strain Genomes Substantially Improves Taxonomic Classification of Alphaproteobacteria. Front Microbiol 2020; 11:468. [PMID: 32373076 PMCID: PMC7179689 DOI: 10.3389/fmicb.2020.00468] [Citation(s) in RCA: 223] [Impact Index Per Article: 55.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 03/04/2020] [Indexed: 11/13/2022] Open
Abstract
The class Alphaproteobacteria is comprised of a diverse assemblage of Gram-negative bacteria that includes organisms of varying morphologies, physiologies and habitat preferences many of which are of clinical and ecological importance. Alphaproteobacteria classification has proved to be difficult, not least when taxonomic decisions rested heavily on a limited number of phenotypic features and interpretation of poorly resolved 16S rRNA gene trees. Despite progress in recent years regarding the classification of bacteria assigned to the class, there remains a need to further clarify taxonomic relationships. Here, draft genome sequences of a collection of genomes of more than 1000 Alphaproteobacteria and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa recognized as problematic long ago but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera and of a variety of genera to other families. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which are confirmed as valuable taxonomic markers. Similarly, analysis of the gene content was shown to provide valuable taxonomic insights in the class. Significant incongruities between 16S rRNA gene and whole genome trees were not found in the class. The incongruities that became obvious when comparing the results of the present study with existing classifications appeared to be caused mainly by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. Another probable cause of misclassifications in the past is the partially low overall fit of phenotypic characters to the sequence-based tree. Even though a significant degree of phylogenetic conservation was detected in all characters investigated, the overall fit to the tree varied considerably.
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Affiliation(s)
- Anton Hördt
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Marina García López
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Jan P. Meier-Kolthoff
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Marcel Schleuning
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Lisa-Maria Weinhold
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
| | - Brian J. Tindall
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Sabine Gronow
- Department of Microorganisms, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
| | - Nikos C. Kyrpides
- Department of Energy, Joint Genome Institute, Berkeley, CA, United States
| | - Tanja Woyke
- Department of Energy, Joint Genome Institute, Berkeley, CA, United States
| | - Markus Göker
- Department of Bioinformatics, Leibniz Institute DSMZ – German Collection of Microorganisms and Cell Cultures, Brunswick, Germany
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Effect of NaCl on aerobic denitrification by strain Achromobacter sp. GAD-3. Appl Microbiol Biotechnol 2017; 101:5139-5147. [DOI: 10.1007/s00253-017-8191-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 02/08/2017] [Accepted: 02/10/2017] [Indexed: 10/20/2022]
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Wang G, Tang M, Wu H, Dai S, Li T, Chen C, He H, Fan J, Xiang W, Li X. Pyruvatibacter mobilis gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122. Int J Syst Evol Microbiol 2016; 66:184-188. [DOI: 10.1099/ijsem.0.000692] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Guanghua Wang
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Mingxing Tang
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Hualian Wu
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Shikun Dai
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Tao Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Chenghao Chen
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
- University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Hui He
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Jiewei Fan
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Wenzhou Xiang
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
| | - Xiang Li
- Key Laboratory of Tropical Marine Bio-resources and Ecology (LMB), Guangdong Key Laboratory of Marine Materia Medica (LMMM-GD), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, PR China
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