石油烃降解菌对环己烷及环己酮的降解作用

Degradation of cyclohexane and cyclohexanone by hydrocarbon degrading bacteria

原油中的环烷烃难以被微生物利用，能长期存在被污染的环境中，对环境造成严重持久的污染。针对环烷烃的污染问题，就微生物降解环己烷，环已酮的特性进行了研究。从胜利油田石油污染土壤中分离到1株能够分别以环己烷、环己酮为唯一碳源的降解菌A-1，经形态及生理生化特征和16SrDNA的全序列测序分析，初步鉴定为节杆菌属（Arthrobacter sp．）.通过摇瓶试验得出其最适生长条件为温度35℃，pH7．0。当盐质量浓度在10～20g·L^-1，环己烷体积分数在0．15~0．35μL·m^-1，环己酮体积分数在0．20-0.30μL·mL^-1时，菌株A-1处于最仕牛长状态。通过GC—MS分析，菌株A-1还能利用原油中C36～C39的链烃，此外还能降解丙酮，辛烷，甲苯等链烃和芳烃。菌株A-1的生长条件和比较宽的底物利用范围的这一研究，为其更广泛的污染环境的生物修复提供了理论依据。

Cycloparaffin in crude oil is difficult to be utilized by microorganisms; thus it exists in polluted environment for a long time and causes a lasting more serious pollution in our environments. This study aimed to find a strain that can degrade cyclohexane and cyclohexanone so as to solve the pollution caused by cycloparaffin. We isolated a degrading bacterial strain A-I which could use cyclohexane or cyclohexanone as the sole carbon source in oil-polluted soil of Shengli oil field. Then it was preliminarily identified that A-1 belonged to Arthrobacter sp. by analysis of its morphology, physiological-biochemical characteristics and sequencing of the whole 16 SrDNA. The optimum growth condition were 35 ℃ and pH 7.0 derived from this experiment. The growth of A-1 strain was in optimum condition when salt concentration, volume fraction of cyclohexane and cyclohexanone were 10-20 g·L^-1, 0.15 -0.35 μL·mL^-1 and 0.20--0.30 μL·mL^-1 respectively. According to the result from GC-MS analysis, the A-1 strain also could degrade aliphatic hydrocarbon of C36-C39 in crude oil. Furthermore, it could degrade aliphatic hydrocarbon and aromatic hydrocarbon such as acetone, octanen, methylbenzene and so on. This study about growth condition and relative wide range of substrate utilization makes it possible that A-1 can be extensively used in bio-restoration of polluted enviroment for the future.