Evaluation of biosurfactant/bioemulsifier production by a marine bacterium.

Planococcus maitriensis Anita I (NCBI GenBank Accession number EF467308) was tested for its biosurfactant/bioemulsifying efficacy. The crude extracellular polymeric substance (EPS) produced by this bacterium contained carbohydrate (12.06%), protein (24.44%), uronic acid (11%) and sulfate (3.03%). The oil spreading potential of this EPS was comparable to Triton X100 and Tween 80. This exopolymer emulsified xylene more efficiently as compared to few standard gums. It also formed stable emulsions (E (1,080)=100) with jatropha, paraffin and silicone oils. The cell free supernatant of this bacterium successfully reduced the surface tension (from 72 to 46.07 mN m(-1)). It also decreased interfacial tension of hexane and xylene. Based on the emulsifying and tensiometric properties, this bacterium or its exopolymer could be used for bioremediation, enhanced oil recovery and in cosmetics.