热带假丝酵母菌对含油污泥的修复潜力研究

Study on remediation potential of oily sludge by Candida tropicalis

关键词:  含油污泥  石油降解菌  表面活性剂  生物修复

Key words:  oily sludge  petroleum degrading bacteria  biosurfactant  bioremediation

摘要:

目的 从油田含油土壤中筛选出了一株石油高效降解菌株—热带假丝酵母菌,实验对其降解石油的特性进行研究。方法 通过红外光谱及薄层色谱对热带假丝酵母菌的代谢产物进行分析,并采用气相色谱法及四组分实验对热带假丝酵母菌降解前后的石油含量及组成进行了检测。结果 实验发现,该菌株的适宜生长温度为30~35 ℃,当温度为32 ℃时,其在7天内对石油的降解率可以达到81.6%,而且对较难降解的芳香烃和沥青质也有良好的降解效果。针对初始含油率为5.21%的含油污泥,其在90天内对石油的降解率达到80.5%。结论 实验所筛选的热带假丝酵母菌能够以葡萄糖和原油为唯一碳源代谢脂肽类生物表面活性剂,该脂肽表面活性剂具有很强的表面活性,对石油具有良好的乳化分散作用,且该菌株对原油具有很高的降解效率。实验所筛选的热带假丝酵母菌在含油土壤的修复方面具有良好的应用潜力。 

Abstract:

Objective A strain of Candida tropicalis, which can degrade petroleum efficiently, was screened from oil-bearing soil in oil field, and its characteristics of degrading petroleum were studied. Methods The metabolites of Candida tropicalis were analyzed by infrared spectroscopy and thin layer chromatography, and the content and composition of petroleum before and after degradation of Candida tropicalis were detected by gas chromatography and four-component experiment. Results It was found that the suitable growth temperature of the strain was 30-35 ℃. When the temperature was 32 ℃, the degradation rate of petroleum could reach 81.6% in 7 days, and it also had a good degradation effect on aromatic hydrocarbons and asphaltenes that were generally difficult to degrade. For oily sludge with initial oil content of 5.21%, the degradation rate of petroleum could reach 80.5% within 90 days. Conclusion sThe Candida tropicalis screened in the experiment can metabolize lipopeptide biosurfactants with glucose and crude oil as the only carbon source. The lipopeptide surfactant has strong surface activity, which has good emulsifying and dispersing effect on crude oil, and the strain has high degradation efficiency on petroleum. The results showed that the selected Candida tropicalis has good application potential in the remediation of oily soil.