一株柴油降解菌的分离及降解条件寻优

Study on Isolation of Diesel-degrading Bacterium and Its Degradation Conditions

从茂名炼油厂附近长期被柴油污染的土壤中分离出1株能够以柴油为惟一碳源和能源的柴油降解菌株,根据其形态和生理学特征鉴定为假单胞菌属(Pseudomonas sp.),命名为DB-1。单因素试验结果表明,DB-1菌株降解的条件范围为温度25～35℃,pH值6.0～8.5,表面活性剂吐温-80浓度50～125 mg·L-1。由正交试验可知,影响DB-1菌株降解的主要因素是温度,其次是pH值和表面活性剂吐温-80,最佳条件组合为温度30℃,pH值7.0,吐温-80的浓度75 mg·L-1,此条件下5d的降解率为65.72%。

A strain （named DB-1） was isolated from the soil which was polluted by diesel around Maoming refinary in Guangdong province. It had an ability of utilizing diesel as sole carbon and energy sources. DB-1 was considered to be belonged to Pseudomonas sp. by morphological characteristics and the physiological and biochemical Indices. The degrading conditions of DB-1 were studied by single factor analysis and orthogonal test. The result of the single factor analysis showed that the suitable conditions were 25-35℃, pH 6.0-8.5 and concentration of surfaetant Tween-80 50-125mg·L^-1. The best operation condition received through the orthogonal test was 30℃,pH7.0,and the surfaetant Tween-80 75mg. L^-1, and 65.72% of the diesel oil could be degraded in 5 days.