Production of a Biosurfactant by Cunninghamella echinulata Using Renewable Substrates and Its Applications in Enhanced Oil Spill Recovery

Abstract

This study aimed to evaluate the production of a surfactant by Cunninghamella echinulata, using agro-industrial residues, corn steep liquor (CSL), and soybean oil waste (SOW). The study had a factorial design, using as a variable response to the reduction of surface tension. C. echinulata was able to produce biosurfactant in assay, CSL (8.82%) and SOW (2%). The results showed that the biosurfactant was successfully produced by C. echinulata and had attractive properties, such as a low surface tension (31.7 mN/m), a yield of 5.18 g/L at 120 h of cultivation, and an anionic profile. It also achieved a reduction in surface tension stability in a wide range of pH values, temperatures, and salinity values. The biosurfactant produced by C. echinulata showed an absence of toxicity to Artemia salina. The influence of the biosurfactant on the viscosity of engine oil, burnt engine oil, diesel, soybean oil post-frying, canola oil, and water was investigated. The results reveal a mechanism for the decrease of the viscosity using hydrophobic substrates and the new biosurfactant solution at 1.5% of the (CMC). This enables the formulation of a low-cost culture medium alternative, based on corn steep liquor and the reuse of soybean oil after frying to produce a biosurfactant. Additionally, performance of the biosurfactant isolated from C. echinulata showed an excellent ability to remove spilled oil, such as diesel (98.7%) and kerosene (92.3%) from marine sand.