Biosurfactant Production by Bacillus cereus, B7 from Lubricant Oil Waste

The present study focused on studying the production of a biosurfactant (BS) from microbial origin. For this respect 12 bacteria and 6 fungi were isolated from different polluted sites in Egypt. Bacillus cereus B7 isolated from kitchen drainage tube gave the highest BS production using oil spreading and emulsification assay techniques. The maximum BS productivity by Bacillus cereus B7 was obtained at the following optimal conditions:, 30C, pH 5, 30h incubation at static condition, inoculum size of 19.36106 cfu; 0.5 ml lubricant oil waste/25 ml medium (2 %, V/V) as the sole C-source, NaNO3 as N-source, Dl--Amino-n-butyric acid and 200ppm LiCl2, none of the tested C-sources and vitamins exhibited further productivity. The BS extracted with CHCl3: C2H5OH in a ratio 2: 1. The organic phase was evaporated in a rotary evaporator to give a white powder. The produced BS exhibited antimicrobial activity against Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa with MIC 5, 5 and 2.5 l, respectively. The BS gave a good potential application as emulsifier.