高寒地区自然堆肥过程中可培养细菌的分离和鉴定

Isolation and identification of culturable bacteria during natural composting in alpine region

为了明确高寒地区油菜秸秆与猪粪在自然堆制过程中可培养细菌菌落数及物种数的变化特征,本试验以油菜秸秆与猪粪的混合物为原料进行堆肥试验,采用稀释平板涂布法分离自然堆肥过程不同阶段的细菌,用平板划线分离法对菌株进行纯化,提取菌株DNA并进行分子鉴定。结果表明:油菜秸秆与猪粪混合物在自然堆制过程中,随着堆肥时间的延长,堆体温度先升高,持续一段时间后逐渐下降并趋于稳定;细菌菌落数先增加后逐渐减少。在整个堆肥发酵过程中,共分离筛选出可培养细菌菌株30株,对21株菌株进行鉴定,由构建的系统发育树结果显示隶属于8个菌属,其中菌属(种)Bacillus velezensis、Stenotrophomonas sp.、Salmonella enterica为堆肥发酵过程中的优势菌。该结果为当地农作物秸秆的高效利用提供理论依据。

The mixture of rape straw and pig manure is used as raw material for composting experiment in order to clarify the variation characteristics of the number and species of culturable bacteria in the natural composting of rape straw and pig manure in alpine region.The bacteria at different stages of natural composting are separated by plate dilution method.The strains are purified by plate scribe separation method.The DNA of the strains is extracted and identified.The results show that in the natural composting of mixing rape straw and pig manure,the pile temperature first increases,then decreases and tends to be stable with high temperature lasting for a period of time;the number of bacterial colonies increases first and then decreases gradually.There are 30 culturable bacterial strains isolated and screened in the whole composting fermentation.In addition,21 strains are identified.The results of phylogenetic tree show that there are 8 bacterial genera,among which Bacillus velezensis,Stenoprophomonas sp.and Salmonella entrica are the dominant strains in the composting fermentation.The results provide a theoretical basis for the efficient utilization of local crop straw.