RESUMO
In this work, biosurfactant production by several yeast strains was evaluated using different culture media. The best results were obtained with the strain Wickerhamomyces anomalus CCMA 0358 growing in a culture medium containing glucose (1g/L) and olive oil (20g/L) as carbon sources. This strain produced 2.6g of biosurfactant per liter after 24h of growth. The crude biosurfactant reduced the surface tension of water to values around 31mN/m, and its critical micelle concentration was 0.9mg/mL. This biosurfactant was characterized through mass spectrometry (MS), and nuclear magnetic resonance (NMR) as a mixture of two different glycolipids, comprising a sugar moiety linked to one or three molecules of oleic acid. To the best of our knowledge, these biosurfactants are structurally different from those previously reported. Furthermore, the crude biosurfactant exhibited antimicrobial activity against several microorganisms, including the pathogens Candida albicans, Escherichia coli, Staphylococcus epidermidis and Streptococcus agalactiae, which opens the possibility for its use in several biomedical applications.