ABSTRACT
The production of surfactants by microorganisms has become an attractive option in the treatment of oil-contaminated environments because biosurfactants are biodegradable and less toxic than synthetic surfactants, although production costs remain high. With the aim of reducing the cost of biosurfactant production, three strains of Pseudomonas (designated P1, P2, and P3) were cultivated in a low-cost medium containing molasses and corn steep liquor as substrates. Following the selection of the best producer (P3), a rotational central composite design (RCCD) was used to determine the influence of substrates concentration on surface tension and biosurfactant yield. The biosurfactant reduced the surface tension of water to 27.5 mN/m, and its CMC was determined to be 600 mg/L. The yield was 4.0 g/L. The biosurfactant demonstrated applicability under specific environmental conditions and was able to remove 80 to 90% of motor oil adsorbed to sand. The properties of the biosurfactant suggest its potential application in bioremediation of hydrophobic pollutants.
