Production of Bioemulsifier by Yeast from the Meyerozyma guilliermondii Complex Isolated from Soil Contaminated with Diesel Oil

Abstract

Abstract The objective of the present study was to analyze different sources of carbon (diesel oil, soybean oil and frying oil) to optimize the production of bioemulsifier by a yeast isolated from soil contaminated with diesel oil. A total of 45 autochthonous yeast were isolated from soil contaminated with diesel oil. Cell growth was achieved in soybean oil and frying oil at 30°C and agitation of 200 rpm. Growth in diesel oil was significantly lower, with a mean of 2.99 g/L. Detection of bioemulsifiers was performed with the emulsification index (E24), the drop-collapse test, the flowability of oil and measurement of surface tension. The mean emulsification indices obtained were between 29.27 % and 43 %, with greater production in the cultivation with diesel oil. This study showed that a stronger emulsifying activity is achieved with yeast growing in a medium with diesel oil, and thus that carbon source should be used for bioemulsifier production.