Functional characterization of a biosurfactant-producing thermo-tolerant bacteria isolated from an o

A Bacillus subtilis strain JA-1 isolated from an oil reservoir was studied.This strain is capable of growth and producing biosurfactant at a temperature of 60 ℃.In nutrient medium it produced biosurfactant which reduced the surface tension from 68.2 mN/m to 28.3 mN/m,with the critical micelle concentration (CMC) of 48 mg/L.The measured surface tension indicated that the biosurfactant possessed stable surface activity at high temperature and a specific range of pH and salt concentrations.The results of thin layer chromatography (TLC) together with FT-IR showed that the metabolic product of strain JA-1 is a lipopeptide biosurfactant.The ability to growth at high temperature and to produce biosurfactant makes strain JA-1 promising for enhanced oil recovery.