Simultaneous Production of Lipases and Biosurfactants in Solid-State Fermentation and Use in Bioremediation

Abstract

This study investigated the simultaneous production of lipases and biosurfactants and the use of culture media containing biocompounds (without precipitation and purification processes) in the bioremediation of contaminated soil. Different concentrations of agroindustrial raw materials, moisture, oil inducers, and nitrogen were studied. The bioremediation assay was evaluated for 90 days, using biodiesel as a contaminant, adding fermented solid culture medium in soil and comparing it to natural attenuation. The culture media was composed of wheat bran:corncob (proportion 80∶20), 5% inducer, and 60% moisture, inoculated with Aspergillus niger, allowing the simultaneous production of biosurfactants [6.67±0.06 Units of Emulsifying activity (UE)] and lipases [10.74±0.54 Units of Lipase (U)]. In the bioremediation assay, the highest degradation of contaminant (64.09%) was found after 60 days using 10% of the fermented solid culture medium containing lipases and biosurfactants. Coproduction of both biocompounds in the fermentation process was allowed, leading to cost reductions and the viability potential of the bioprocess on an industrial production scale, as well as its environmental application in the treatment of oily contaminants.