Properties of the Biosurfactant Produced by Candida Sphaerica Cultivated in Low-Cost Substrates

Abstract

Many biosurfactants have been produced, although few are produced due to the high costs of production and purification processes. Given the potential for biotechnological application of these compounds in the oil and pharmaceutical industries, the optimization of the use of two industrial wastes, corn steep liquor and ground–nut oil refinery residue e as low cost nutrients for the production of a biosurfactant by Candida sphaerica (UCP 0995) was studied. Then the properties of the biosurfactant was described, and its isolation, preliminary chemical characterization. In this paper we used an optimized medium with distilled water supplemented with 9 % ground nut oil refinery residue and 9 % corn steep liquor as substrates to produce biosurfactants by Candida sphaerica, at 28°C during 144h under 200rpm. The isolated biosurfactant was formed with a yield of 9g/L. The biosurfactant showed high surface tension reducing activity the 25 mN/m, a small CMC value (0.025 %), thermal (5-120°C) and pH (2-12) stability with respect to surface tension reducing activity and to emulsification activity and tolerance under hight salt concentrations (2-10 %). The biosurfactant was characterized as glycolipid and recovered 95 % of motor oil adsorbed in a sand sample, showing great potential to be used in bioremediation processes, especially in the petroleum industry.