目的驯化、筛选降解五氯酚的高效菌,并对其生长特性和降解条件进行研究。方法采用活性污泥曝气与密度梯度驯化方法,以五氯酚为唯一碳源,定时定量逐步提高五氯酚浓度,连续驯化8周。将平板涂布分离纯化的细菌进行降解试验,筛选降解优势菌,探讨其生长的适宜温度、不同渗透压下的生长特点和降解五氯酚的适宜条件,并根据形态和生理生化特征进行菌种的初步鉴定。结果分离出3株五氯酚降解菌,其中1株对五氯酚48h的降解率为98.6%,且在温度30℃、pH6.0、五氯酚初浓度0.2~0.4g/L的条件下,降解效果最好。该菌在30℃生长最快,为耐盐菌,初步鉴定为醋杆菌属。结论通过活性污泥曝气与密度梯度驯化法可获得五氯酚高效降解菌,并取得良好的降解效果。
Objective To acclimate,screen the dominant bacteria for degrading pentachlorophenol and its growth characteristics and degradation conditions study.Methods Active sludge aeration and method of density gradient were used to acclimate the sludge.Using pentachlorophenol as a sole carbon source,it was increased step by step in continuous eight weeks.The biodegradation test on pentachlorophenol was conducted after isolation,purification of the dominant bacteria.The suitable temperature,the growth characteristics under different osmotic pressure and the proper degradation conditions of the dominant bacteria were investigated.According to the morphological characteristic,physiological and biochemical,the strain was preliminarily identified.Results Three strains of dominant bacteria were screened.The degradation rates of one strain among them on pentachlorophenol could reach to 98.64% in 48h.The degradation effect would be better when the temperature was 30℃,pH was 6,and the concentration of pentachlorophenol was 0.2-0.4g /L.The strain could grow best under 30℃.It was halotolerant bacteria and identified as Acetobacter.Conclusion The dominant bacteria could be got through density gradient acclimatization in the active sludge aeration basin and its degradation effect on pentachlorophenol was obvious.