中国东部水稻土壤丁酸互营降解微生物的地理分布格局

Biogeographic Patterns of Microbial Communities Associated with Syntrophic Butyrate Degradation in Paddy Soils in Eastern China

沿纬度梯度收集中国东部34个水稻土壤样品,在实验室条件下,以丁酸钠为底物,进行二次厌氧富集实验。运用微生物高通量测序技术,分析样地水稻土壤中丁酸互营降解过程的微生物群落特征、功能活性及互营单胞菌相对丰度地理分布格局。结果表明,丁酸降解产甲烷的延滞期(3~14天)随着样地纬度的升高而加长,但最大产甲烷速率没有显著的差异。环境因子相关分析结果表明,丁酸降解细菌的关键类群为互营单胞菌(Syntrophomonas),互营单胞菌的相对丰度主要受年平均温度(MAT)的影响。互营单胞菌相对丰度较大的样地,丁酸完全降解所需时间较短。丁酸互营降解微生物的群落结构表现出显著的距离衰减关系(p<0.05),表明微生物群落的构建同时受到空间距离和环境因子的驱动。

The authors collected 34 paddy soil samples along the latitude from eastern China.Enrichment experiment was conducted under anaerobic conditions with sodium butyrate as the sole substrate.The authors investigated the microbial community characteristics and the functional activity of syntrophic butyrate degradation and the biogeographic patterns of relative abundance of Syntrophomonas in these soils by Illumina sequencing of 16S rRNA genes.The lag phase of CH4 production(3–14 days)increased towards higher latitudes,whereas the maximum rate of CH4 production did not.The correlation analysis on influencing factors revealed that Syntrophomonas was the key syntrophic bacterial taxon associated with butyrate degradation and its relative abundance was significantly influenced by mean annual temperature(MAT).The sampling sites with a relatively high abundance of Syntrophomonas had a shorter time for the complete degradation of butyrate.Distance-decay patterns characterized by a steeper slope were found in microbial communities associated with syntrophic butyrate degradation(p<0.05),indicating that the construction of microbial communities was driven by both spatial distance and environmental factors.