一株耐低温石油烃降解菌的分离鉴定及其降解特性

Isolation and Characterization of a Low Temperature Hydrocarbon-Degrading Bacterial Strain

目的:从污染环境中分离耐低温石油降解菌,并对其降解特性进行研究。方法:采用摇瓶富集培养和平板划线分离的方法,得到一株能以原油为碳源、能源生长的细菌菌株,采用分子生物学方法对该降解菌进行初步鉴定。结果:从天津大港油田污染土壤和水体中分离到一株耐低温石油降解菌DSY171,该菌株能够在10℃条件下,以石油为惟一碳源生长。经过对其形态特征、生理生化及16S rDNA序列分析,初步鉴定该菌株归属红球菌属。菌株DSY171在低温条件下(10～15℃)12 d的石油降解率显著优于常温条件(20～30℃),原油降解率为60%左右;菌株DSY171的pH适应范围较广,初始pH值为6～9时均能代谢生长,但在偏碱性环境下(pH7～9)的代谢生长好于偏酸性环境(pH6～7)。除了降解石油外,菌株DSY171对柴油、食用油等不同碳源也均能够降解代谢,具有一定的碳源利用广谱性。结论:耐低温石油降解菌DSY171的分离及其降解特性的研究,为生物学方法解决低温环境石油污染问题提供了高效菌种,在环境微生物学理论研究和实践应用中具有一定的意义和价值。

Objective:To isolate and characterize a low temperature hydrocarbon-degrading bacterial strain.Methods:A bacterial strain DSY171 that degrades hydrocarbons was isolated from the sludge samples by flask enrichment culture and streak plate.Also,it was identified by 16S rDNA sequence analysis.Results:A bacterial strain that degrades hydrocarbons was isolated from the sludge samples polluted by the municipal solid waste in the beach of Bohai sea.It was identified as Rhodococcus sp.DSY171 according to its morphology,and biochemical properties,and 16S rDNA sequence analysis.Further study indicated the optimal pH and temperature for cell growth and hydrocarbon degradation were 7~9 and 10~15℃,respectively,and the optimal degradation of hydrocarbon in 12 days was 60%.Broad-spectrum degradation capability study of DSY171 showed that n-hexadecane,diesel oil and cooking oil could all be degradated.Conclusion:This study is valuable for environmental microbiology research and application.The isolated low temperature hydrocarbon-degrading bacterial strain DSY171 will contribute to solve the oil pollution in the low temperature environment.