烷烃降解菌SY16的筛选、鉴定及降解能力测定

Isolation, characterization, and alkane degradation potential of hydrocarbon-degrading bacteria SY16

油田生产和运输中经常发生原油落地以及漏油现象,造成大量的石油进入地表土壤,从而产生环境污染。针对原油对土壤产生的环境污染问题,对微生物降解烷烃的能力进行了研究。在以正十六烷为唯一碳源的HDM培养基中,从扶余油田东区采油三厂经常被含油废水浸泡的土壤中,分离、筛选出一株高效降解正烷烃的菌株SY16。经形态学观察和生理生化特征研究,鉴定为施氏假单胞杆菌(Pseudomonas stutzeri)。通过摇瓶试验得出两菌株的最适生长条件为30℃,培养基初始pH 8.0,摇床转速为180 r/min,接种量为1.0%。在最适生长条件下,分别对不同初始质量浓度烷烃进行降解率试验。结果表明,两菌株降解正烷烃的能力显著,当培养基中初始正烷烃含量为50 mg/L时,24 h能全部降解。当混合烷烃中各烷烃的初始质量浓度为50 mg/L时,在24 h对正十烷、正十二烷、正十六烷和正十八烷的降解率分别达到47.0%、42.6%、38.8%、36.2%。

In the process of production and transportation of crude oil, soil around oil wells is easy to be contaminated by crude oil, and environment may be damaged. For solving the problem of soil contamination at oilfield, microbiological degradation for hydrocarbon is studied experimentally. Using Hydrocarbon degradation medium （HDM） which contains n-hexadecane as the sole carbon source, one hydrocarbon-degrading Bacteria, which have high degrading capacity for n-alkanes, are isolated and screened out from soil from Fuyu oilfield. Through morphological observation and character studies of physiology and biochemistry, the strains SYI 6 are identified as Pseudomonas stutzeri. By tests in shaking flasks, it is deten＇ained that the conditions of growth for the strain is 30 ℃, with shaker rotary speed 180r/min, and inoculum amount 1.0%, and the initial pH of HDB is 8.0. Under these conditions for optimum growth, the degradation rate experiments on different initial concentrations of alkanes are carried out. The results indicate that the ability of SYI6 for degrading n-alkanes is marked. The n-alkanes can be degraded almost 100% if the initial concentration at about 50mg/L in HDB. With the initial concentration of individual compound in the alkanes mixture at about 50mg/L, the degrading rates of n-decane, n-dodecane, n-pentadecane and n-hexadecane are 47.0%, 42.6%, 38.8% and 36.2%, respectively.