陕北石油降解菌的筛选及培养基的优化

Screening of Oil-Degrading Strains in Northern Region of Shaanxi and Optimizing of Culture Medium

本文从陕北油区被石油污染的土壤中筛选出3株高效石油降解菌(分别为NS-1、NS-3、NS-5),利用比色法测定了试验菌株对石油的降解率,其中NS-1在石油初始浓度为4 g/L时对石油的降解率达89.63%。利用Minitab软件通过PB试验筛选、Box-Behnken中心组合设计和响应面分析,在发酵培养基的基础上,对NS-1的培养基进行了优化。在硫酸铵、硫酸镁、氯化钠、葡萄糖4种培养基成分中,硫酸铵、硫酸镁、氯化钠3个因素是影响菌株NS-1生长的关键因素,优化后的培养基配方为:葡萄糖2.0%、硫酸镁0.9%、硫酸铵0.1%、氯化钠0.4%。与LB培养基相比,优化后的培养基可使菌株NS-1在培养20 h时增产38.7%。

Three strins, named as NS-1, NS-3 and NS-5, which could degradate oil effectively, were isolated from the oil-polluted soil in Northern Region of Shaanxi and the degradation effect was determined by the method of colourimetry. The results showed that NS-1 could make the oil degrade by 89.63% when the original concentration of oil was 4 g/L. The culture medium of NS-1 was optimized by minitab software by the way of PB testing, Box-Behnken center combination design and the response surface analysis based on the fermentation medium. It was indicated that MgSO4, （NH4）2SO4 and NaC1 were key factors for NS-1 growth, and the optimal recipe of the culture medium was 2.0% glucose, 0.9% MgSO4, 0.1% （NH4）2SO4, 0.4% NaC1, and the yield of NS-I was increased by 38. 7% after culturing for 20 h, compared to that with LB culture medium.