银川地区规模化奶牛养殖场粪污可培养细菌种群分布多样性研究

The Study of Diversity of Culturable Bacteria Community in Manure From Large-scale Dairy Farms in Yinchuan

以银川市规模化奶牛养殖场的新鲜粪便、堆积粪便、污水和环境土壤4种样品为材料,对培养获得的429株细菌分离株进行鉴定。结果显示,规模化奶牛养殖场粪污中具有大量且种类丰富的可培养细菌,鉴定出的358株分离株分属于4个门、6个纲、15个目、23个科、39个属和102个种,主要集中于厚壁菌门(Firmicutes)、放线菌门(Actinobacteria)和变形菌门(Proteobacteria);进一步分析病原菌数量发现条件致病菌占88. 55%(317/358),在种水平上主要为金黄色葡萄球菌(Staphylococcus aureus)(11/358)、大肠埃希菌(Escherichia coli)(33/358)和托尔豪特链球菌(Streptococcus thoraltensis)(8/358)。由此可见,奶牛养殖场粪污对人和动物有潜在健康风险,若不经处理直接排放或还田施用,将对养殖安全和环境卫生造成巨大威胁。

The present study aims to investigate the culturable bacteria community of isolates from 4 kinds of samples(fresh fecal samples,accumulated manure without treatment samples,soil samples and waste water samples)collected from 3 large-scale dairy farms in Yinchuan.The samples were first diluted and plated on 8 different kinds of separation media such as nutrient agar medium,blood agar medium and MacConkey agar medium.Each of the single colony was then purified at least 3 times with the corresponding media for further analysis.After Gram staining,each isolate was further identified by VITEK 2 Compact automatic microbial biochemical identification system or 16S rDNA gene sequencing analysis.A total of 429 isolates were obtained from the samples through isolation and purification.After further analysis with VITEK 2 Compact automatic microbial biochemical identification system and 16S rDNA gene sequencing,a total of 358 strains were identified,these strains were distributed in 4 phyla,6 classes,15 orders,23 families,39 genera and 102 species.The rates of pathogenic bacteria in the samples were also calculated.Results show that conditional pathogenic bacteria accounted for 88.55%(317/358)of the total.The main conditional pathogens in the strains were S.aureus(11/358),E.coli(33/358)and S.thoraltensis(8/358).Strains mainly concentrated in the Firmicutes,Actinobacteria and Proteobacteria,and the conditional pathogenic bacteria may seriously threaten the human and animal as well as environmental if these fecal samples are discarded or used as fertilizer without proper treatment.