Chen Song-Can, Ji Jiaheng, Popp Denny, Jaekel Ulrike, Richnow Hans-Hermann, Sievert Stefan M, Musat Florin
Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
Department of Environmental Microbiology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany.
Environ Microbiol. 2022 Apr;24(4):1964-1976. doi: 10.1111/1462-2920.15956. Epub 2022 Mar 7.
The metabolic potential of the sulfate-reducing bacterium Desulfosarcina sp. strain BuS5, currently the only pure culture able to oxidize the volatile alkanes propane and butane without oxygen, was investigated via genomics, proteomics and physiology assays. Complete genome sequencing revealed that strain BuS5 encodes a single alkyl-succinate synthase, an enzyme which apparently initiates oxidation of both propane and butane. The formed alkyl-succinates are oxidized to CO via beta oxidation and the oxidative Wood-Ljungdahl pathways as shown by proteogenomics analyses. Strain BuS5 conserves energy via the canonical sulfate reduction pathway and electron bifurcation. An ability to utilize long-chain fatty acids, mannose and oligopeptides, suggested by automated annotation pipelines, was not supported by physiology assays and in-depth analyses of the corresponding genetic systems. Consistently, comparative genomics revealed a streamlined BuS5 genome with a remarkable paucity of catabolic modules. These results establish strain BuS5 as an exceptional metabolic specialist, able to grow only with propane and butane, for which we propose the name Desulfosarcina aeriophaga BuS5. This highly restrictive lifestyle, most likely the result of habitat-driven evolutionary gene loss, may provide D. aeriophaga BuS5 a competitive edge in sediments impacted by natural gas seeps. Etymology: Desulfosarcina aeriophaga, aério (Greek): gas; phágos (Greek): eater; D. aeriophaga: a gas eating or gas feeding Desulfosarcina.
目前，硫酸盐还原菌脱硫八叠球菌属菌株BuS5是唯一能够在无氧条件下氧化挥发性烷烃丙烷和丁烷的纯培养物。通过基因组学、蛋白质组学和生理学分析，对其代谢潜力进行了研究。全基因组测序表明，菌株BuS5编码一种单一的烷基琥珀酸合酶，该酶显然启动了丙烷和丁烷的氧化过程。蛋白质基因组学分析表明，生成的烷基琥珀酸盐通过β氧化和氧化型伍德-Ljungdahl途径被氧化为二氧化碳。菌株BuS5通过经典的硫酸盐还原途径和电子分叉来保存能量。自动注释管道显示其具有利用长链脂肪酸、甘露糖和寡肽的能力，但生理学分析和对相应遗传系统的深入分析并不支持这一点。同样，比较基因组学揭示了菌株BuS5的基因组精简，分解代谢模块明显稀少。这些结果表明，菌株BuS5是一种特殊的代谢专家，只能利用丙烷和丁烷生长，我们建议将其命名为嗜气脱硫八叠球菌BuS5。这种高度受限的生活方式很可能是栖息地驱动的进化基因丢失的结果，可能为嗜气脱硫八叠球菌BuS5在受天然气渗漏影响的沉积物中提供竞争优势。词源：嗜气脱硫八叠球菌，aério（希腊语）：气体；phágos（希腊语）：食者；嗜气脱硫八叠球菌：一种以气体为食或摄取气体的脱硫八叠球菌。
