Screening and Characterization of Benzene Degrading Bacterium in Oil-contaminated Soil

A benzene-degrading bacterium(strain DQ0306) was isolated from oil-contaminated soil around one oil well in Daqing,China after a series of experiments.DQ0306 could take benzene as sole carbon and energy resources and degrade benzene efficiently with degrading rate 35.7%.The bacterial strain was initially identified as Flavobacterium based on its morphology,physiological,biochemical properties.The impact of bacteria itself and the environmental conditions on benzene degradation was also studied.The growth curve of DQ0306 and biochemical degradation curve of benzene by the bacterial strain were similar;they all entered exponential phase about 20 hours later and the two stationary phases appeared after over 44 hours.The optimal conditions for the degradation of benzene were 30 ℃,pH 6.5~6.7,inoculation 10%,shaking rotate 180~220 r·min-1,reaction time 32 h respectively.DQ0306 may provide a possible channel for improving the degradation efficiency of benzene hydrocarbons which are usually degraded rather difficultly in petroleum components.