应用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)技术对农业废物好氧堆肥过程中氨氧化细菌(ammonia-oxidizingbacteria,AOB)种群结构随时间的变化情况进行了研究,结果表明,AOB群落的Shannon-Weaver指数初始值为2.58,堆肥结束时为2.02,多样性整体呈下降趋势.通过对部分优势条带进行克隆测序,发现Nitrosospira和Nitrosomonas为堆肥中AOB的优势种属,其中Nitrosomonas存在于整个堆肥过程中,是耐受性较强的种属.使用Canoco 4.5软件对获得的氨氧化细菌种群数据与不同时期堆体温度、pH、含水率、NH 4+-N、NO 3--N等环境因子的相关性进行冗余分析(redundancy analysis,RDA).RDA二维排序图显示堆肥前期样点分布较为集中,后期样点分布较为分散,表明AOB群落结构在堆肥高温期前期(4~9 d)变化较小,而在高温期后期(9~12 d)特别是降温期(12~25 d)演替尤为剧烈.基于手动选择的RDA分析结果表明,堆体温度、NH 4+-N和NO 3--N对AOB群落演替有着显著的影响(P〈0.05),且前2个因子达到了极显著水平(P〈0.01).
The dynamic succession of ammonia-oxidizing bacteria(AOB)community during the agricultural waste composting was investigated using the polymerase chain reaction-denaturing gradient gel electrophoresis(PCR-DGGE).The changes of pile temperature,pH,moisture content,soluble NH+4-N and NO-3-N were measured.DGGE results showed that the Shannon-Weaver index changed from 2.58 to 2.02 during the composting process,which reflected the diversity trends downward overall.Nitrosospira and Nitrosomonas were dominant species.Nitrosomonas eutropha,which was found throughout the whole composting process,was identified as a kind of well-tolerated species.Redundancy analysis(RDA)was applied to explore the correlation between the dynamic succession of AOB community and composting physic-chemical parameters.Compared with the slight change referring to its structure during the earlier phase of thermophilic period(4-9 d),the AOB community experienced a more significant change during the later phase of thermophilic period(9-12 d) as well as the following temperature falling phase(12-25 d).Significant relationships have been found between pile temperature,soluble NH+4-N(P〈0.01)and NO-3-N(P〈0.05)with the dynamic succession of AOB community,which suggested those three parameters were likely to influence,or be influenced by AOB during the agricultural waste composting.