产生物表面活性剂的石油降解菌Acinetobacter BHSN的研究

Biosurfactant-Producing Petroleum-Degrader-Acinetobacter BHSN

从石油污染土壤中分离筛选获得1株产生物表面活性剂的石油降解菌株BHSN。经形态观察、生理生化试验、16S rDNA序列分析等将其鉴定为不动杆菌属(Acinetobacter sp.)。研究表明,BHSN菌株能降解石油中C13～C32正构烷烃。BHSN菌株生长和产生物表面活性剂的最适温度为25～30℃,最适pH为5.0～8.5。LB培养基中添加终质量浓度为10g.L-1葡萄糖能促进菌体的生长,但不利于表面活性剂的合成;添加蔗糖、乳糖、麦芽糖和木糖对菌体的生长和表面活性剂的合成均有促进作用,其中麦芽糖的促进作用最强。初步研究表明,BHSN菌株产的生物表面活性剂为脂肽类;BHSN发酵液的表面张力由初始68.3mN.m-1降低到28.6mN.m-1。

A strain of biosurfactant-producing petroleum-degrader-BHSN was isolated from petroleum-contaminated soil. Strain BHSN was identified as Acinetobacter sp. according to its morphological, physiological, and biochemical features and 16S rDNA sequences. Strain BHSN was capable of degrading C13 - C32 n-alkanes in crude oil. It grew and produced biosurfactant the most in medium with temperature ranging from 25 to 30℃, and pH 5.0 - 8.5. In LB medium, addition of 10 g . L^-1 glucose promoted growth of BHSN, but not hindered production of biosurfactant. Addition of 10 g . L ^-1 sucrose, lactose, maltose or xylose stimulated both growth and biosurfactant synthesis of BHSN. The biosurfactant produced by Strain BHSN was primarily identified as lipopeptide based on TLC and FT-IR analyses. The biosurfactants it produced in fermented medium decreased the surface tension of the medium from 68.3 to 28.6 mN . m^-1.