Potential of killer yeasts utilization for “cachaça” production
Authors
Jaqueline Lima
Universidade Estadual do Ceará
Laura Bruno
Embrapa Agroindústria Tropical,
Jonas Silva
Universidade Federal do Ceará
Antônio Casimiro
Universidade Federal do Ceará
Keywords:
Killer activity. Killer phenotype. Fermentation.
Abstract
Two hundred and thirty yeasts were isolated from “cachaça” sugarcane juice and evaluated for the presence of killer phenotype. Sixteen (7.0%) isolates were positive for this characteristic. Incubation temperature and pH of cultivation environment influenced killer toxin production. When incubation temperature was 25 °C all isolates produced toxin at pH 4.2; 4.5 and 5.0. However, killer activity was not detected nor when microorganisms were growth at pH 3.0, nor when incubation temperature was raised above 30 °C. Isolates ability to ferment sugarcane juice and ethanol production was also tested. The fermentation yield of isolate 188 was 45.8%, with 85.1% of fermentative efficiency. The killer character presence and fermentation characteristics of isolate 188 show that it is a promising microorganism to be used on fermentative processes for ethanol production.