The yeast-like fungus Aureobasidium thailandense LB01 produces a new biosurfactant using olive oil mill wastewater as an inducer

Abstract

In this study, the biosurfactant production by an Aureobasidium thailandense LB01 was reported for the first time. Different agro-industrial by-products (corn steep liquor, sugarcane molasses, and olive oil mill wastewater) were evaluated as alternative low-cost substrates. The composition of the culture medium was optimized through response surface methodology. The highest biosurfactant production (139 ± 16 mg/L) was achieved using a culture medium containing yeast extract (2 g/L); olive oil mill wastewater (1.5%, w/w); glucose (6 g/L) and KH2PO4 (1 g/L) after 48 h of fermentation. The partially purified biosurfactant exhibited a critical micelle concentration of 550 mg/L, reducing the surface tension of water up to 31.2 mN/m. Its molecular structure was found to be similar to a lauric acid ester. The biosurfactant exhibited a better performance than the chemical surfactant sodium dodecyl sulfate (SDS) in oil dispersion assays, thus suggesting its potential application in bioremediation.