Estudo da fermentação submersa não aerada por Saccharomyces cerevisiae para determinação dos parâmetros de consumo de glicose e produção de glicerol e etanol

Abstract

A study of non-aerated submerged fermetation by Saccharomyces cerevisiae was carried out evaluating the effect of pH on the coefficients: (I) of Pirt equation; and (II) of Garden model. In the tests performed, increasing the pH slowed glucose comsumption, and, cell growth and ethanol production decreased with increasing pH from 4.5 to 9.0. Specifically, with regard to ethanol, the high coefficient values associated with the growth from the non-associated growth factor production associated indicate growth. However, for maximum production of glycerol there was a decrease in the coefficient values associated with growth and an increase in coefficient values not associated with the growth. Glucose consumption for cellular maintenance was significant (0,2gglucose / ((gcell.h)) to pH 7.0 and 7.5, where there was a greater production of glycerol. In conclusion it was possible to observe the existence of a relationship between the saline and osmotic stress in the metabolism of Saccharomyces cerevisiae by increasing the maintaining glucose consumption, and glycerol production disassociation cell growth, indicating the intra and extracellular glycerol accumulation.