从加油站附近的被污染土壤中分离到9株柴油降解菌,选取降解率较好的菌A、菌C,根据其形态观察、生理生化特性以及16S rDNA基因序列相似性分析,初步鉴定为芽孢杆菌属,菌A为短小芽孢杆菌,菌C为枯草芽孢杆菌.单因素实验表明,在10 mL/L的柴油降解培养基中,菌A的最适温度为37℃,pH为8.0,接种量15％,第7d降解率达到42％；菌C的最适温度为37 ℃,pH为7.5,接种量10％,第7d降解率达到40％.这两株菌在柴油降解过程中都会产生脂肽类表面活性剂,引起表面张力下降,柴油降解培养基最初的表面张力是64.13 mN/m,5d后,菌A和菌C表面张力分别下降到37.61 mN/m,42.02 mN/m.%Nine bacteria strains were isolated from the contaminated soil near the fueling station. Strain A and C with relatively higher diesel oil biodegradation ability were chosen for further study. They were identified as Bacillus sp. Based on their morphological, physiological, biochemical features and 16S rDNA sequences. Strain A was B. Pumilus and strain C was B. Subtilis. Parameters affecting biodegradation activity were investigated to obtain the optimal degradation condition. Under the optimal degradation conditions, the degradation rates of strain A and C after 7 days were 42% and 40% , respectively. The results showed that both strain A and C produce biosurfactant during the process of diesel oil degradation, resulting in the surface tension decreased from 64. 13 mN/m to 37. 61 mN/m and 42. 02 mN/m, respectively. FTIR results indicated that the biosurfactants prouduced were both lipopepitides.
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