School of Environmental Sciences, University of East Anglia, Norwich, NR4 7TJ, UK.
School of Biological Sciences, University of the Punjab, Quaid-i-Azam Campus, Lahore, 54000, Pakistan.
ISME J. 2022 Jul;16(7):1705-1716. doi: 10.1038/s41396-022-01211-0. Epub 2022 Mar 22.
Natural gas seeps release significant amounts of methane and other gases including ethane and propane contributing to global climate change. In this study, bacterial actively consuming short-chain alkanes were identified by cultivation, whole-genome sequencing, and stable-isotope probing (SIP)-metagenomics using C-propane and C-ethane from two different natural gas seeps, Pipe Creek and Andreiasu Everlasting Fire. Nearly 100 metagenome-assembled genomes (MAGs) (completeness 70-99%) were recovered from both sites. Among these, 16 MAGs had genes encoding the soluble di-iron monooxygenase (SDIMO). The MAGs were affiliated to Actinobacteria (two MAGs), Alphaproteobacteria (ten MAGs), and Gammaproteobacteria (four MAGs). Additionally, three gaseous-alkane degraders were isolated in pure culture, all of which could grow on ethane, propane, and butane and possessed SDIMO-related genes. Two Rhodoblastus strains (PC2 and PC3) were from Pipe Creek and a Mycolicibacterium strain (ANDR5) from Andreiasu. Strains PC2 and PC3 encoded putative butane monooxygenases (MOs) and strain ANDR5 contained a propane MO. Mycolicibacterium strain ANDR5 and MAG19a, highly abundant in incubations with C-ethane, share an amino acid identity (AAI) of 99.3%. We show using a combination of enrichment and isolation, and cultivation-independent techniques, that these natural gas seeps contain a diverse community of active bacteria oxidising gaseous-alkanes, which play an important role in biogeochemical cycling of natural gas.
天然气渗漏释放大量甲烷和其他气体，包括乙烷和丙烷，这些气体导致了全球气候变化。在这项研究中，通过培养、全基因组测序和使用来自两个不同天然气渗漏点（Pipe Creek 和 Andreiasu Everlasting Fire）的 C-丙烷和 C-乙烷进行的稳定同位素探测（SIP）-宏基因组学，鉴定出了积极消耗短链烷烃的细菌。从这两个地点都回收了近 100 个宏基因组组装基因组（MAG）（完整性 70-99%）。其中，16 个 MAG 具有编码可溶性二铁单加氧酶（SDIMO）的基因。MAG 隶属于放线菌（两个 MAG）、α变形菌（十个 MAG）和γ变形菌（四个 MAG）。此外，还在纯培养中分离出了三个气态烷烃降解菌，它们都可以在乙烷、丙烷和丁烷上生长，并具有与 SDIMO 相关的基因。两个 Rhodoblastus 菌株（PC2 和 PC3）来自 Pipe Creek，一个 Mycolicibacterium 菌株（ANDR5）来自 Andreiasu。菌株 PC2 和 PC3 编码假定的丁烷单加氧酶（MO），而菌株 ANDR5 含有丙烷 MO。Mycolicibacterium 菌株 ANDR5 和 MAG19a 在 C-乙烷孵育中丰度很高，它们的氨基酸同一性（AAI）为 99.3%。我们使用富集和分离以及培养依赖和非培养技术的组合表明，这些天然气渗漏点含有一个活跃的细菌群落，它们可以氧化气态烷烃，在天然气的生物地球化学循环中发挥着重要作用。
