好氧堆肥中amoA硝化细菌群落动态变化

Dynamic Change of amoA Nitrifying Bacteria Community During Aerobic Composting

为减少堆肥氮素损失,优化堆肥工艺,以牛粪和玉米秸秆为材料进行高温好氧堆肥,采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)和产物序列分析法,研究了堆肥不同阶段amoA硝化细菌群落结构组成和多样性的动态变化及与堆肥理化因子的相关性。结果表明:经高温期amoA硝化细菌类群发生明显演替,降温期检测到前期不存在的硝化类群,属于β-变形菌纲(β-Proteobacteria)中的亚硝化单胞菌属(Nitrosomonas)。堆肥过程始终存在的优势菌群属于β-变形菌(β-Proteobacteria)中的亚硝化螺菌属(Nitrosospira)和不可培养细菌(Uncultured bacteria)。堆肥不同时期amoA硝化细菌多样性指数发生变化,升温至高温期减小,降温期增大,腐熟期减小。冗余分析(RDA)结果表明,铵态氮含量和温度与amoA硝化细菌群落结构组成显著相关(P<0.05),是影响其动态变化的关键理化因子。

In order to reduce nitrogen loss during the composting,and to optimize the composting process,high temperature aerobic composting was conducted with cow manure and maize stalk as materials. Polymerase chain reactiondenaturing gradient gel electrophoresis （PCRDGGE） technique and sequence analysis method were used to analyze the dynamic change of the community composition and diversity of amoAnitrifying bacteria during composting different periods, which correlated with composting physiochemical parameters. The results showed that the nitrifying bacteria groups obviously changed after thermophilic period. Some new nitrifying bacteria groups were detected during cooling period. These groups belonged to Nitrosomonas sp. in the class of βProteobacteria. Dominant nitrifying bacteria during composting belonged to Nitrosospira sp. in the class of βProteobacteria and uncultured bacteria. The diversity index of nitrifying bacteria changed during composting process, which decreased from mesophilic to thermophilic stage, increased at cooling stage and then decreased at mature stage. Redundancy analysis （RDA） results showed that the ammonium nitrogen content and temperature of compost were the keys to the physiochemical factors significantly affected nitrifying bacteria community composition （P〈0.05）.