Proteome and fermentative parameters of Saccharomyces cerevisiae CAT-1 under Very High Gravity Fermentation (VHGF) using sugarcane juice

Abstract

Alcoholic fermentation is an important process in the modern world, allowing the production of ethanol for several applications. Different Saccharomyces cerevisiae strains have been used for this purpose, such as CAT-1, a strain resistant to different stress factors. Hence, our aim was to analyze some fermentative parameters and the proteome of S. cerevisae CAT-1 under Very High Gravity Fermentation (VHGF) using sugarcane juice as fermentative medium. The yeast was cultured in the must with the sucrose concentration adjusted to 2%, 14%, 21% and 30%, for 10 h at 30 ºC. The cell viability was 96-100% for all sucrose concentrations analyzed and the biomass increased for each condition as time function. The highest ethanol recovery was obtained under 30% sucrose. Considering the S. cerevisiae CAT-1 proteome under 14% and 30% sucrose, qualitative and quantitative differences were found in the protein expression. Important enzymes for fermentation, such as enolase and one alcohol dehydrogenase isoform were more expressed at 30% sucrose than with 14% sucrose. The yeast S. cerevisiae CAT-1 is an interesting strain to be used for fermentation under VHGF technology using sugarcane juice, allowing high ethanol recovery with increased expression of proteins related to alcoholic fermentation and viability as well.