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

高小朋任军鹏唐政龙袁茂林

GAO Xiao-Peng REN Jun-Peng TANG Zheng-Long YUAN Mao-Lin

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4g／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茵株NS-1在培养20h时增产38．7％。图4表5参14

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 NaCl 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% NaCl,and the yield of NS-1 was increased by 38.7% after culturing for 20 h,compared to that with LB culture medium.