{"title":"<i>Methanococcoides cohabitans</i> sp. nov., a marine methylotrophic methanogen isolated from an anaerobic methane-oxidizing enrichment culture.","authors":"Sihan Li, Lewen Liang, Sidra Erum Ishaq, Tariq Ahmad, Yijing Dong, Jialin Hou, Gunter Wegener, Fengping Wang","doi":"10.1099/ijsem.0.006685","DOIUrl":null,"url":null,"abstract":"<p><p>Enrichment cultures of archaea and bacteria performing the anaerobic oxidation of methane (AOM) regularly contain persistent methanogens. Here, we isolated the marine methanogen <i>Methanococcoides cohabitans</i> sp. nov. strain LMO-2<sup>T</sup> from a long-term AOM enrichment culture from the Northern Gulf of Mexico. Strain LMO-2<sup>T</sup> is Gram-stain-negative, irregular 0.5-1 µm coccus without flagella. It utilizes a variety of methylated compounds including methanol, monomethylamine, dimethylamine and trimethylamine for growth and methanogenesis. However, it does not grow on formate, acetate, dimethyl sulphate, H<sub>2</sub>/CO<sub>2</sub>, betaine and choline. The optimal conditions for growth were observed within a temperature range of 30-35 °C, a pH range of 7.0-8.0 and a salinity range of 2-4% NaCl. Based on the similarity and phylogeny of the 16S rRNA gene and genomic sequence, strain LMO-2<sup>T</sup> is classified within the genus <i>Methanococcoides</i>. Among the isolated type strains of the genus, strain LMO-2<sup>T</sup> exhibited the highest 16S rRNA gene sequence identity with <i>Methanococcoides vulcani</i> SLH33<sup>T</sup> (99.4%). The digital DNA-DNA hybridization and average nucleotide identity based on genome sequence showed that strain LMO-2<sup>T</sup> shared the highest similarity with <i>Methanococcoides orientis</i> LMO-1<sup>T</sup>, with values of 27.3% and 83.4%, respectively. In conclusion, we isolated a methylotrophic methanogen from an AOM culture, and the isolated strain LMO-2<sup>T</sup> represented a novel species of the genus <i>Methanococcoides</i>, for which the name <i>Methanococcoides cohabitans</i> sp. nov. is proposed. The type strain is LMO-2<sup>T</sup> (=CGMCC 1.18051<sup>T</sup>=KCTC 25774<sup>T</sup>).</p>","PeriodicalId":14390,"journal":{"name":"International journal of systematic and evolutionary microbiology","volume":"75 3","pages":""},"PeriodicalIF":2.0000,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"International journal of systematic and evolutionary microbiology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1099/ijsem.0.006685","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q4","JCRName":"MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Enrichment cultures of archaea and bacteria performing the anaerobic oxidation of methane (AOM) regularly contain persistent methanogens. Here, we isolated the marine methanogen Methanococcoides cohabitans sp. nov. strain LMO-2T from a long-term AOM enrichment culture from the Northern Gulf of Mexico. Strain LMO-2T is Gram-stain-negative, irregular 0.5-1 µm coccus without flagella. It utilizes a variety of methylated compounds including methanol, monomethylamine, dimethylamine and trimethylamine for growth and methanogenesis. However, it does not grow on formate, acetate, dimethyl sulphate, H2/CO2, betaine and choline. The optimal conditions for growth were observed within a temperature range of 30-35 °C, a pH range of 7.0-8.0 and a salinity range of 2-4% NaCl. Based on the similarity and phylogeny of the 16S rRNA gene and genomic sequence, strain LMO-2T is classified within the genus Methanococcoides. Among the isolated type strains of the genus, strain LMO-2T exhibited the highest 16S rRNA gene sequence identity with Methanococcoides vulcani SLH33T (99.4%). The digital DNA-DNA hybridization and average nucleotide identity based on genome sequence showed that strain LMO-2T shared the highest similarity with Methanococcoides orientis LMO-1T, with values of 27.3% and 83.4%, respectively. In conclusion, we isolated a methylotrophic methanogen from an AOM culture, and the isolated strain LMO-2T represented a novel species of the genus Methanococcoides, for which the name Methanococcoides cohabitans sp. nov. is proposed. The type strain is LMO-2T (=CGMCC 1.18051T=KCTC 25774T).
期刊介绍:
Published by the Microbiology Society and owned by the International Committee on Systematics of Prokaryotes (ICSP), a committee of the Bacteriology and Applied Microbiology Division of the International Union of Microbiological Societies, International Journal of Systematic and Evolutionary Microbiology is the leading forum for the publication of novel microbial taxa and the ICSP’s official journal of record for prokaryotic names.
The journal welcomes high-quality research on all aspects of microbial evolution, phylogenetics and systematics, encouraging submissions on all prokaryotes, yeasts, microfungi, protozoa and microalgae across the full breadth of systematics including:
Identification, characterisation and culture preservation
Microbial evolution and biodiversity
Molecular environmental work with strong taxonomic or evolutionary content
Nomenclature
Taxonomy and phylogenetics.