Produção de biossurfactantes por leveduras

Abstract

The main aim of this work was to evaluate the biosufarctant production by five wild yeasts species Yarrowia lipolytica CCMA 0357 (from Amazon soil), Yarrowia lipolytica CCMA 0242 (Kefir), Wickerhamomyces anomalus CCMA 0358 (coffee fermentation), Lindnera saturnus CCMA 0243 (Cerrado soil), and Cryptococcus humicola CCMA 0346 (Cerrado soil), in eight different culture media. Wickerhamomyces anomalus CCMA 0358 cultivated in olive oil presented lowest value of surface tension (32.05 mN/m). A rotatable center composite design (RCCD) was performed for optimization of parameters in order to increase the production of the biosurfactant. The inclusion of yeast extract was 89% significant and the surface tension after optimization was 31.5 mN / m. Batch fermentations were carried out with stirring 500 rpm, and increasing the surface tension of 29.3 mN / m after 24 hours and yield of 2.60 g / L. Antimicrobials and oil recovery tests were performed with the biosurfactant. For the first species of Streptococcus sanguis, Streptococcus oralis and Streptococcus agalactiae, were growth inhibited by 100 % crude biosurfactant, Candida albicans has 78 % inhibition of Staphylococcus epidermitis and 66%. Twenty percent of the oil was recovered using only the supernatant of the fermentation, cell-free, containing the biosurfactant. The biosurfactant studied in this work was characterized as glycolipid, wherein the lipid phase comprises oleic acid. However, the glycidic phase could be identified, indicating that it is a novel compound. These results showed for the first time the production of biosurfactants by Wickerhamomyces anomalus CCMA 0358 which can be used in different biotechnological applications.