Xu Jiangbing, Jia Zhongjun, Lin Xiangui, Feng Youzhi
International Center for Ecology, Meteorology and Environment (IceMe), School of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China; State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing, 210008, China.
Microbiol Res. 2017 Sep;202:36-42. doi: 10.1016/j.micres.2017.05.004. Epub 2017 May 26.
Paddy methane (CH) production is biologically dominated by methanogenic archaea that metabolize a variety of organic and/or inorganic carbon sources. Though formate is easily dissimilated into H/CO, formate-metabolizing methanogenic archaea are distinct from CO-utilizing methanogen taxa. The identity of formate-metabolizing methanogenic archaea in paddy soil remains elusive. In this investigation, molecular approaches based on stable isotope probing (SIP) technique were conducted to identify the formate-metabolizing methanogenic archaea in paddy soil. CH emission monitor, real-time quantitative PCR (qPCR) and Denaturing Gradient Gel Electrophoresis (DGGE) analyses consistently indicated that some methanogenic archaea metabolized C-labeled formate in microcosm and accounted for a large portion of formate-metabolizing archaea in anoxic paddy soil. Phylogenetic identification further found that this guild was affiliated to Methanobacteriaceae. Taken together Methanobacteriaceae could be the dominant formate-metabolizing methanogenic archaea and play an important role in the CH production in paddy soil. These findings would extend the extant knowledge on paddy methanogenic archaea and microbial-driven paddy CH emission.
稻田甲烷（CH）的产生在生物学上主要由产甲烷古菌主导，这些古菌能够代谢多种有机和/或无机碳源。尽管甲酸盐很容易异化分解为H/CO，但利用甲酸盐的产甲烷古菌与利用CO的产甲烷菌类群不同。稻田土壤中利用甲酸盐的产甲烷古菌的身份仍然不明。在本研究中，采用基于稳定同位素探测（SIP）技术的分子方法来鉴定稻田土壤中利用甲酸盐的产甲烷古菌。CH排放监测、实时定量PCR（qPCR）和变性梯度凝胶电泳（DGGE）分析一致表明，一些产甲烷古菌在微观世界中代谢了C标记的甲酸盐，并且在缺氧稻田土壤中占利用甲酸盐古菌的很大一部分。系统发育鉴定进一步发现，这个类群隶属于甲烷杆菌科。综合来看，甲烷杆菌科可能是利用甲酸盐的主要产甲烷古菌，并且在稻田土壤CH产生中发挥重要作用。这些发现将扩展关于稻田产甲烷古菌和微生物驱动的稻田CH排放的现有知识。
