Abstract: 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.

Key words: petroleum-degrader, Acinetobacter sp., alkane biodegradation, biosurfactant, fermenting condition