石油高效降解细菌的筛选及其降解特性研究

A Study on isolation,selecting,and degradating characteristics of bacteria from the oil-polluted soil

以山东省东营市胜利油田附近被石油污染的土壤作为分离样品,连续富集筛选出以原油为唯一碳源、能源进行生长繁殖的石油高效降解菌株X P和X B.经菌落形态、生理生化反应,初步鉴定2株菌分属为芽孢杆菌属(Bacillus sp.)和假单胞菌属(Pseudomonas sp.);通过生物表面活性剂活性试验,分析了2株菌的油降解能力.结果表明:2株菌均具溶血和排油特性,溶血圈直径高达3.6 cm、排油圈直径高达4.9 cm,可以产生生物表面活性剂,并且溶血圈和排油圈直径与生物表面活性剂的产生呈正相关.室内培养箱实验测定,2株菌对石油的降解率分别为72.3%(X P)和61.2%(X B)(原油含量/土壤总量×100%=10%),在此过程中2株菌对石油降解的速度、能力有显著效果.室外堆制试验中,60 d处理后,锯末、小麦秸秆、菌剂及N、P营养物协同处理组降解效果明显,降解率高达54.0%-68.2%,说明外源添加物能提高微生物的降解能力.结论:筛选得到的菌株X P和X B是两株高效降解石油的菌株,在土壤中能很好地利用石油进行生长代谢,可应用于石油污染实际生物修复工程.

Petroleum-degrading strains X P and X B were obtained by enrichment culture from contaminated soil samples collected from Shengli Oil Fields in Dongying city,Shandong province and with crude oil as the only carbon source and energy source for growth and reproduction.The strains were identified as Bacillus sp.and Pseudomonas sp.based on their morphology,physio-biochemical characteristics.The oil degrading capacities of two strains were analyzed by activity test of biological surfactants.The results indicated that both strains showed hemolytic and oil-discharging characteristics,with the hemolytic circle diameter up to 3.6 cm and the oil-discharging circle diameter up to 4.9 cm,which could produce biological surfactants.The diameter of hemolytic circle and oil drain circle is positively correlated with the activity of biological surfactant.Indoor incubator test results showed that the degradation rate of 2 strains on oil was 72.3%(X P)and 61.2%(X B),respectively(crude oil content/soil quantity×100%=10%).In this process,the two strains had a significant effect on the rate and ability of oil degradation.In the outdoor stacking test,after 60d treatment,the group treated with sawdust,wheat straw,bacteria and N and P nutrients had obvious degradation effect,and the degradation rate was as high as 54.0%-68.2%,indicating that the exogenous additives could improve the degradation ability of microorganisms.Conclusions:The strain X P and X B were two high-efficiency oil degradation bacterial strains.It can be well used for growth in soil,and can be applied to the actual bioremediation project of oil pollution.