Production of Surface Active Glycolipid by Serratia marcescens NSK-1 Isolated from Petroleum Contaminated Soil

Biosurfactant-producing Serratia marcescens NSK-1 strain was isolated from soil contaminated with petroleum products. The organism, when grown in mineral salts medium with sucrose as sole carbon source, produced a surface-active anthrone-positive glycolipid. The biosurfactant was partially purified by liquid-liquid partition chromatography in chloroform-methanol mixture (1:1) and silica gel chromatography. It reduced the surface tension of distilled water from 72 dynes/cm to 40 dynes/cm and exhibited good emulsification activity with some vegetable oils and hydrocarbons. The biosurfactant exhibited stable surface activity over a wide range of temperature (30-100°C), pH (2-12) and salt concentration. There was no significant toxic effect shown by the biosurfactant towards mice when tested using the World Health Organization guidelines. DOI: 10.3126/on.v8i1.4308