基于高通量测序分析牛粪堆肥中细菌群落动态变化

摘要

文章以奶牛粪便和玉米秸秆作好氧堆肥,堆肥持续36d.采用16S rRNA基因高通量测序技术分析堆肥过程中细菌群落特征,通过Alpha多样性分析、样本层级聚类分析和距离热图(Heatmap)分析,结果表明,堆肥过程中细菌群落结构发生显著变化.门分类水平细菌群落结构分析表明,变形菌门(Proteobacteria)和厚壁菌门(Firmicutes)在堆肥前期和高温期相对丰度较高,酸酐菌门(Acidobacteria)在堆肥后期相对丰度较高;属分类水平细菌群落结构分析表明,在堆肥初始阶段各属相对丰度相近,环脂酸芽孢杆菌属(Tumebacillus)在堆肥升温期占优势,肠杆菌属(Enterobacter)、未命名细菌(norank_c_OPB54)和玫瑰弯菌属(Roseiflexus)为堆肥高温期优势类群,类似芽球菌属(Blastocatella)出现在堆肥高温期末期,在降温期和腐熟期成为优势菌属.Spearman相关性分析表明,除肠杆菌属(Enterobacter)、未命名细菌(norank_c_OPB54)、假黄色单胞菌属(Pseudoxanthomonas)外剩余11个属均与含水率、有机物降解率、C/N和NH4+-N/NO3--N之间呈显著相关,肠杆菌属与pH呈极显著正相关(P＜0.001),未命名细菌(norank_c_OPB54)与温度呈极显著正相关(P＜0.001).研究表明,在牛粪堆肥期间细菌群落结构发生显著变化,细菌群落结构变化与堆肥理化因子存在相关关系.%In this study,high throughput sequencing of 16S rRNA gene was employed to elucidate bacterial community dynamics during dairy manure and com straw composting.The aerobic composting process lasted for 36 days.Alpha diversity analysis,cluster analysis and distance heatmap analysis revealed that the bacterial community structure significantly changed during composting.The bacterial community structure analysis at the phylum taxonomic level showed the relative abundances of Proteobacteria and Firmicutes were higher at the early and thermophilic stage of composting,and the relative abundance of Acidobacteda was higher at later stage of composting.The bacterial community structure analysis at the genus taxonomic level showed the relative abundance of each genus was similar at the initial stage of the composting,Tumebacillus was dominant at the mesophilic stage.Enterobacter,norank_c_OPB54 and Roseiflexus were the dominant bacteria during the thermophilic stage.Blastocatella appeared at the end of the thermophilic stage of composting.It became the dominant genus at the cooling and maturity stage.Spearman correlation analysis showed that,apart from Enterobacter,norank c OPB54 and Pseudoxanthomonas,the remaining 11 genera were significantly correlated with water content,organic matter degradation rate,C/N and NH4+-N/NO3--N,respectively.Enterobacter and norank c OPB54 were positively correlated with pH and temperature,respectively (P＜0.001).The results showed that bacterial community structure changed significantly during cow manure composting.Meanwhile,the change of bacterial community structure was related to physicochemical parameters of composting.