Recuperação de biossurfactante produzido por Kluyveromyces marxianus

Abstract

Surfactants of biological origin, also called biosurfactants are produced from microorganisms, and have advantages over those of chemical origin, such as biodegradability in soil and water. They also have low toxicity and can be used in the food, cosmetics and pharmaceutical industry. The objective of this work was to recover the biosurfactant produced by Kluyveromyces marxianus, as well as to determine the biomass and emulsifying index. For biosurfactant recovery, the methods of ammonium sulfate precipitation and ethanol precipitation were tested. Biomass production was determined by analytical scale gravimetry and the emulsifying index was verified using two hydrocarbons, gasoline and kerosene. Based on the experimental results, the ammonium sulfate precipitation extraction technique produced no precipitate. The recovery using ethanol, in the ratio of 5: 1, was efficient for the recovery of biosurfactant produced, but with low yield. The emulsifying index was determined by the height of the emulsion formed, being the result expressed as a percentage, where kerosene (44.64%) presented higher emulsifying index when compared to gasoline (1.92%). The average biomass production was 5.4 g L-1. The presented results showed that it is possible to recover the biosurfactant produced by the yeast Kluyveromyces marxianus, but it is indicated that higher concentrations of ammonium sulfate as well as larger volumes of ethanol are used for biosurfactant extraction.