4株降解低温粪污水芽孢杆菌的分离·鉴定及其降解效率研究

目的]获得可在低温环境下高效降解粪污水的芽孢杆菌。方法]从大型养殖场及活性污泥、下水道等低温环境下采集样品,分离并筛选耐冷菌株,通过扫描电镜观察获得菌株的形态特征,分析其16S rRNA基因测序,构建系统发育树,初步确定菌株的菌属;对其进行鉴定后将其添加到污水生物反应器中对猪场粪污水进行净化,分析粪污水中化学需氧量(COD)、生物需氧量(BOD)及溶解氧(DO)变化情况。结果]这4株菌均为蜡样芽孢杆菌;在粪污水里添加这4株菌的复合菌液后,粪污水的COD值从5 585.40 mg/L降至1 093.97 mg/L,去除率达80.40%;BOD值从680.00 mg/L降至600.00 mg/L,去除率为11.76%;DO值大幅度上升,增加率为75.00%。结论]复合菌在粪污水处理方面表现出了较高的降解能力,可为污染物生物修复提供优良的菌种资源,具有广阔的应用前景。

Isolation and Identification of Four Bacillus Species with Degradation of Fecal Sewage at Low Temperature and Their Degradation Efficiency

Objective] To obtain Bacillus which could efficiently degrade fecal sewage at low temperature.Method] Samples were collected from the large farms, activated sludge, sewer and other low temperature environment.Cold resistant strains were isolated and screened.Obser-vation of scanning electron microscope could obtain the morphological characteristics of strains.The 16S rRNA gene sequence was analyzed. Phylogenetic tree was constructed.And the bacterial genus were preliminarily detected.After identified, they were added into wastewater bio-logical reactors to purify fecal sewage in pig farm.chemical oxygen demand(COD), biological oxygen demand (BOD) and dissolved oxygen ( DO) were analyzed in the fecal sewage. Result] The four strains all belonged to Bacillus cereus.After adding the composite solution of four strains into fecal sewage, COD value declined from 5 585.40 to 1 093.97 mg/L with the removal rate of 80.40%; BOD value reduced from 680.00 to 600.00 mg/L, with the removal rate of 11.76%.DO value enhanced greatly with the increasing rate reaching 75.00%.Conclu-sion] The compound bacteria shows relatively high degradation ability, provides high-quality strain resources for the bio-remediation of pollu-tants, and has broad application prospect.