Utilisation of oil-based waste for biosurfactant production

Abstract

Chemical surfactants produced in large amounts globally have severe adverse effects on environment and human health due to their non-degradable and toxic nature. Eco-friendly biosurfactants with high stability, biodegradability, and low toxicity are the need of the hour. However, biosurfactants are less preferred due to high substrate cost and cumbersome extraction process. This study focused on repurposing of lipid-rich waste like coconut oil cake, rice husk and used cooking oil as a substrate for bacterial biosurfactant production. P. aeruginosa and B. subtilis were evaluated for production and P. aeruginosa was found to be an efficient biosurfactant producer. Among the substrates, coconut oil cake gave maximum yield of 19 mg/ml. The study also focussed on optimisation of biosurfactant extraction using organic solvents and precipitation methods. The yield obtained was maximum using chloroform and methanol (2:1) extraction method. The product obtained was characterised using standard methods and confirmed for its properties. It also exhibited promising antimicrobial activity against gram-positive species.