Deyan Liu Weixin Ding Zhongjun Jia Zucong Cai. The impact of dissolved organic carbon on the spatial variability of methanogenic archaea communities in natural wetland ecosystems across China. Appl Microbiol Biotechnol 2012 96:253–263.
Abstract
Significant spatial variation in CH4 emissions is a well-established feature of natural wetland ecosystems. To understand the key factors affecting CH4 production the variation in community structure of methanogenic archaea in relation to substrate and external environmental influences
was investigated in selected wetlands across China using denaturing gradient gel electrophoresis. Case study areas were the subtropical Poyang wetland the warmtemperate Hongze wetland the cold-temperate Sanjiang marshes and the alpine Ruoergai peatland on the Qinghai–Tibetan Plateau. The topsoil layer in the Hongze wetland exhibited the highest population of methanogens; the lowest was found in the Poyang wetland. Maximum CH4 production occurred in the topsoil layer of the Sanjiang Carex lasiocarpa marsh the minimum was observed in the Ruoergai peatland. CH4 production potential was significantly correlated with the dissolved organic carbon (DOC) concentration but not with the abundance or diversity indices of methanogenic archaea. Phylogenetic analysis and DOC concentration indicated a shift in the dominant methanogen from the hydrogenotrophic Methanobacteriales in DOCrich wetlands to Methanosarcinaceae with a low affinity in wetlands with relatively high DOC and then to the acetotrophic methanogen Methanosaetaceae with a high affinity in wetlands with low DOC or with high DOC but rich sulfate-reducing bacteria. Therefore it is proposed that the dominant methanogen type in wetlands is primarily influenced by available DOC concentration. In turn the variation in CH4 production potential in the wetlands of eastern China is attributable to differences in the DOC content and the dominant type of methanogen present.
