Application of the Biosurfactant produced by Candida lipolytica in the Remediation of Heavy Metals

Abstract

Soil that is accidentally contaminated with petroleum hydrocarbons can be remediated by physical, chemical, or biological methods. However, new trends in soil and water restoration avoid introducing synthetic chemicals. Among the remediation techniques available for contaminated sites, bioremediation is regarded as environmentally friendly because it preserves the soil structure, requires little energy input, and involves the complete destruction or immobilization of the contaminants, although the efficiency of biodegradation of oil pollutants is often limited by their poor water solubility. Despite their advantages, due to the high production costs biosurfactants are not extensively used. In this sense the lipopeptide biosurfactant produced by Candida lipolytica (UCP 0988), is an attractive alternative to the synthetic surfactants, showing properties in bioremediation of heavy metals. The biosurfactant reduced the surface tension of the production medium from 50 mN/m to 25 mN/m, with a yield of 8 g/L, after 72 h of fermentation. The biosurfactant showed a CMC of 0.03 %. The lipoprotein removed 96 % of Zn and Cu, and reduced the concentration of Pb, Cd and Fe. The optimization process of biosurfactant production, which permitted the reduction of costs, suggests its ample utilization according to commercial requirements.