Advanced Water Management Centre , The University of Queensland , St Lucia, Brisbane , Queensland 4072 , Australia.
School of Resource and Safety Engineering , Central South University , Changsha 410083 , China.
Environ Sci Technol. 2019 Jul 2;53(13):7371-7379. doi: 10.1021/acs.est.9b00077. Epub 2019 Jun 18.
There is great interest in microbial conversion of methane, an abundant resource, into valuable liquid chemicals. While aerobic bioconversion of methane to liquid chemicals has been reported, studies of anaerobic methane bioconversion to liquid chemicals are rare. Here we show that a microbial culture dominated by Candidatus 'Methanoperedens nitroreducens', an anaerobic methanotrophic archaeon, anaerobically oxidizes methane to produce acetate, indirectly via reaction intermediate(s), when nitrate or nitrite is supplied as an electron acceptor under a rate-limiting condition. Isotopic labeling tests showed that acetate was produced from certain intracellular storage compounds that originated from methane. Fluorescence in situ hybridization and Nile red staining demonstrated that polyhydroxyalkanoate in M. nitroreducens was likely one of the intracellular storage compounds for acetate production, along with glycogen. Acetate is a common substrate for the production of more valuable chemicals. The microbial conversion discovered in this study potentially enables a new approach to the use of methane as a feedstock for the chemical market.
人们对将丰富的资源甲烷转化为有价值的液体化学品的微生物转化非常感兴趣。虽然已经有报道称甲烷可以通过需氧生物转化为液体化学品，但关于甲烷的厌氧生物转化为液体化学品的研究却很少。在这里，我们展示了一种微生物培养物，其中主要是厌氧甲烷营养古菌的候选种“Methanoperedens nitroreducens”，当硝酸盐或亚硝酸盐作为电子受体在限速条件下供应时，该培养物可以将甲烷厌氧氧化为乙酸盐，间接通过反应中间体（s）。同位素标记试验表明，乙酸盐是由源自甲烷的某些细胞内储存化合物产生的。荧光原位杂交和尼罗红染色表明，M. nitroreducens 中的聚羟基烷酸酯可能是用于产生乙酸盐的细胞内储存化合物之一，还有糖原。乙酸盐是生产更有价值化学品的常见底物。本研究中发现的微生物转化可能为利用甲烷作为化学原料提供了一种新方法。
