Identification Of The Bacteria Strains On Crude Oil Biodegradation And Research On The Synergistic Effect For Enhancement

Crude oil pollutant posed a critical hazard for ecological system and humanhealth. Bio-treatment to crude oil pollutant had become a key-point in studies ofenvironmental protection field because its advantages in safety, long-acting，bargainprice and no secondary pollution. In this paper, we isolated4crude oil degradingstrains and studied their characters in crude oil biodegradation, enhancement of crudeoil biodegradation by synergistic effect of the degrading strain and the biosurfactantproducing strain was achieved, and the synergistic effect was explained from bothsubstrate synergetic metabolism and the effect of biosurfactant in medium.4crude oil degrading strains and1biosurfactant producing strain were isolatedfrom soil samples polluted by crude oil for a long time. The degrading strains wereidentified asRhodococcus sp. JZX-01, Acinetobacter sp. XM-02, Pseudomonas sp.JZX-02, Ochrobactrum sp. JZX-03, Arthrobacter sp. LM-01; the biosurfactantproducing strain was identified and designated as Pseudomonas sp. XM-01.The most effective strain of the5degrading strains was Rhodococcus sp. JZX-01,95.7%alkane hydrocarbons (diesel: crude oil,4:1, v/v) was degraded by the strain at30℃,200rpm in3days, and65.27±5.63%crude oil in9days. The strain was able todegrade crude oil at a low temperature,47%and23%of crude oil were degraded in9days at20℃and10℃, respectively. This strain could reduce the surface tension from72×103N/m to31×103N/m with alkane hydrocarbons as its sole carbon and energysource.Two strains isolated from soil polluted by crude oil were identified andnominated as Pseudomonas sp. XM-01and Acinetobacter sp. XM-02. P.sp.XM-01could produce biosurfactant (identified as rhamnolipid. Enhancement of alkanehydrocarbons and crude oil biodegradation was achieved by a new idea to mix thedegrading strain and the biosurfactant producing strain. Reasons for the enhancementwere preliminarily investigated from the synergistic effectsof biosurfactant productionand the substrates sequencing utilization by the observation of the changing structureof the mixed strains. It is concluded that this new way for the enhancement of crudeoil biodegradation would be a safe and long-acting method for potential bio-treatmentto crude oil contaminated waterand soil.