Resume

Yeast identification in fermentation process are very important, because some strains cause industrial losses. Cane quality and operational conditions during the processing may influence yeasts diversity, stability during fermentation and ethanol yield. This study performed yeasts diversity present in fermentation process and ethanol yield in 10 cycles, using sugarcane juice attacked by spittlebug (Mahanarva fimbriolata). Fermentation was conducted in a batch procedure with yeast recovery through centrifugation. Baker yeast Saccharomyces cerevisiae was used as initial inoculum. Yeasts analyses were performed by Pulsed Field Gel Eletrophoresis (PFGE) and isoenzimatic profiles. Nineteen yeasts profiles was founded in two experiment seasons (May/June and October), and most diversity was observed when cane was more damaged, indicating that the cane quality has significant influences in yeast diversity during the fermentation process.