Avaliação de leveduras kveik para produção de etanol a partir da farinha desengordurada de milho (Zea mays)

Abstract

In 2017, Kveik yeasts gained prominence in the academic scene. Originating from regions of Northern Europe, such as Norway and Russia, these strains are traditionally used in beer production. Recently, they have been identified as part of the Saccharomyces cerevisiae species. However, their use has been overshadowed by scientific advances and the Industrial Revolution, which favored isolated strains. Kveik yeasts are notable for their rapid fermentation and adaptability to variations in density and temperature. With the global challenge of reducing dependence on fossil fuels, Brazil stands out for its renewable energy matrix and expertise in ethanol production. Thus, this study proposed to evaluate Kveik yeasts for ethanol production from corn. Out of 12 acquired cultures, 15 distinct strains were isolated. The Kveik Voss and Ebbegarden strains proved to be the most promising, showing growth in media with ethanol contents above 17% (w/w), with the latter being selected for experimental tests. After conducting a Plackett-Burman design with 11 factors, it was concluded that only sugar concentration and inoculum rate had a significant effect (p<0.05) on ethanol productivity. Thus, the results of the Rotatable Central Composite Design indicated that the optimal fermentation condition for ethanol production was at 30°C, 29 °Brix, and an inoculum rate of 7.5*10^6 cells/ml. During data validation, ethanol production was 8.07% for strain Ca11 and 8.82% (w/w) for strain Eb3, 12% above the values predicted by the model for the ideal conditions.