STUDY OF YEAST STRAINS Saccharomyces cerevisiae FROM BIODIVERSITY ENVIRONMENTAL IN ALCOHOLIC FERMENTATION

Native strains of Saccharomyces cerevisiae from the industrial ethanol process were isolated and have been tested with standard CAT-1 strain, which was selected, and widely used in ethanol production in southest of Brazil in batch fermentation system with cells recycles (Melle-Boinot). The strains were reactivated in synthetic culture media and then inoculated into clarified sugar cane juice at 4 degrees Brix for growth until it reaches a cell concentration 1.0 x 10(8)/mL. After this, the cells were inoculated in a sugar cane juice at concentration 20 degrees Brix by six fermentative cycles. After each cycle were carried out the following analyses: ethanol concentration, pH, biomass, viability and budding cells. The data were analyzed statistically using variance analyses (ANOVA) and averages compared by Tukey test at 5% probability. The results show the best performance for that CAT-1 in fermentative efficiency than strains 18 and 19, mainly by the ethanol concentration. The 18 and 19 strains showed similar results of performance with characteristics for the ethanol production.