稻田土壤亚硝酸盐型甲烷厌氧氧化菌群落结构的时空特征

稻田是温室气体甲烷的重要排放源之一,对全球气候变化具有重要影响.由隶属于NC10门的Candidatus Methylomirabilis oxyfera(M.oxyfera)-like细菌介导的亚硝酸盐型甲烷厌氧氧化是控制稻田甲烷排放的新途径.目前,有关此类微生物群落在稻田土壤中的时空分布特征及其环境影响因素尚不明确...

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

Paddy fields are one of the most important methane sources,which have great impacts on climate change.The nitrite-dependent anaerobic methane oxidation,by NC10 phylum bacteria-Candidatus Methylomirabilis oxyfera(M.oxyfera)-like bacteria,is a new process regulating methane emission from paddy fields.However,little is known about the spatial and temporal variations of M.oxyfera-like bacterial communities and the regulating factors in paddy soils.We investigated the community composition,diversity,and abundance of M.oxyfera-like bacteria in 0-40 cm depth of paddy soils at key growth stages of rice,including tillering,jointing,flowering,and milky stages.Results of high-throughput sequencing showed that community composition of M.oxyfera-like bacteria differed significantly among different soil layers,while no significant variation was observed among different rice growth stages.The diversity of M.oxyfera-like bacteria increased with soil depth.Real-time quantitative PCR showed that the 16 S rRNA gene abundance of M.oxyfera-like bacteria ranged from 5.73×10⁶ to 2.56×10⁷ copies·g^-1(dry weight),with the highest gene abundance in the 10-20 cm layer.Further,the abundance of these bacteria showed a decreasing trend with rice growth.Soil organic carbon content and soil pH were correlated with the M.oxyfera-like bacterial community structures and abundance.In all,our results suggested a certain degree of heterogeneity of spatial and temporal distribution of M.oxyfera-like bacterial communities in paddy soils,which was largely influenced by soil organic carbon and soil pH.