稻田土壤反硝化厌氧甲烷氧化菌的时空分布与群落结构分析

由"Candidatus Methylomirabilis oxyfera"主导发生的以甲烷和亚硝酸盐为底物的反硝化厌氧甲烷氧化反应(nitrite-dependent anaerobic methane-oxidizing,n-damo)的发现,将生物地球化学碳循环和氮循环以新的方式结合起来.本研究以夏季和冬季江阴稻田土壤柱状样品为研究对象,对稻田土壤M.oxyfera-like菌的时空分布和群落结构进行了考察.M.oxyfera-like菌16S rRNA基因的定量PCR结果显示M.oxyfera-like菌的丰度随着土壤深度的增加而增加,且无明显季节性差异,60~200 cm深度的稻田土壤是M.oxyfera-like菌的高丰度区域.M.oxyfera-like菌pmo A基因的系统发育分析和生物多样性分析显示M.oxyfera-like菌的群落结构具有一定的时空异质性,且生物多样性随着土壤深度的增加而增加.这些结果都说明江阴稻田深层土壤(60~200 cm)是适宜M.oxyfera-like菌生存的生态环境.

Spatial-temporal distribution and community structure analysis of nitrite-dependent anaerobic methane-oxidizing bacteria in paddy soil

The discovery of nitrite-dependent anaerobic methane-oxidizing (n-damo) mediated by "Candidatus Methylomirabilis oxyfera" with nitrite and methane as substrates has connected biogeochemical carbon and nitrogen cycles in a new way. In this study, the spatial-temporal distribution and community structure of M.oxyfera-like bacteria were investigated in Jiangyin paddy soil cores in summer and winter. The results of quantitative PCR investigation of M.oxyfera-like bacterial 16S rRNA genes showed that the abundance of M.oxyfera-like bacteria increased with the depths of soil without obvious seasonal variation and the 60~200 cm depths were high abundance regions. Phylogenetic analysis and biological diversity analysis of M.oxyfera-like bacterial pmoA genes showed that community structure of M.oxyfera-like bacteria had high spatial-temporal heterogeneity in the paddy soil and the biological diversity also increased with the depths. The results obtained in this study showed that deep layer of Jiangyin paddy soil cores (60~200 cm) was a favorable environment for the growth of M.oxyfera-like bacteria.