UNSW Water Research Centre, School of Civil and Environmental Engineering, UNSW Australia, Sydney, NSW, 2052, Australia.
ISME J. 2019 May;13(5):1168-1182. doi: 10.1038/s41396-018-0338-z. Epub 2019 Jan 14.
Isoprene is the most abundant biogenic volatile organic compound (BVOC) in the Earth's atmosphere and plays important roles in atmospheric chemistry. Despite this, little is known about microbiological processes serving as a terrestrial sink for isoprene. While aerobic isoprene degrading bacteria have been identified, there are no known anaerobic, isoprene-metabolizing organisms. In this study an H-consuming homoacetogenic enrichment was shown to utilize 1.6 μmoles isoprene h as an electron acceptor in addition to HCO. The isoprene-reducing community was dominated by Acetobacterium spp. and isoprene was shown to be stoichiometrically reduced to three methylbutene isomers (2-methyl-1-butene (>97%), 3-methyl-1-butene (≤2%), 2-methyl-2-butene (≤1%). In the presence of isoprene, 40% less acetate was formed suggesting that isoprene reduction is coupled to energy conservation in Acetobacterium spp. This study improves our understanding of linkages and feedbacks between biogeochemistry and terrestrial microbial activity.
异戊二烯是地球大气中含量最丰富的生物挥发性有机化合物（BVOC），在大气化学中起着重要作用。尽管如此，人们对作为异戊二烯陆地汇的微生物过程知之甚少。虽然已经鉴定出好氧异戊二烯降解细菌，但目前还没有已知的厌氧、异戊二烯代谢生物。在这项研究中，一个 H 消耗同型乙酰生成菌富集物被证明除了 HCO 之外，还可以将 1.6 µmoles 异戊二烯 h 作为电子受体利用。异戊二烯还原群落主要由醋杆菌属（Acetobacterium）主导，异戊二烯被化学计量还原为三种甲基丁烯异构体（2-甲基-1-丁烯（>97%）、3-甲基-1-丁烯（≤2%）、2-甲基-2-丁烯（≤1%））。在异戊二烯存在的情况下，形成的乙酸盐减少了 40%，这表明异戊二烯还原与醋杆菌属的能量守恒相关。这项研究增进了我们对生物地球化学和陆地微生物活动之间联系和反馈的理解。
