tornarem os dias mais leves. Aos demais colegas e amigos do laboratório. Ao meu namorado, Italo, obrigada imensamente por ouvir, compreender e apoiar. Por suas palavras sinceras. E, por sua companhia. Ao laboratório vizinho, BELa, pelo suporte técnico-científico e por fornecer o uso de equipamentos. Em especial, à Thamires pelas análises em HPLC. E, ao Gabriel, pelo compartilhamento de informações técnicas e recomendações Obriagada ao Prof. Dr. Adriano Rodrigues Azzoni por possibiliatar a realização das análises no Laboratório de Biomol. Agradeço ainda às parcerias que possibilitaram a realização de análises. Especificamente, gostaria de mencionar Tatiana Corrêa do GaTE Lab (Laboratório de Genômica e Elementos de Transposição), do Instituto de Biociências da USP. À Profa. Dra. Louise pelo apoio técnico científico e pelo suporte nas análises de MALDI-TOF no CEPEMA.Às instituições que apararam este projeto de pesquisa, a EMBRAPII e a FUSP. À SINOCHEM por financiar esse projeto de pesquisa.

Background Corn and sugarcane account for the world's most used feedstocks for ethanol production. Although, a single fermentation line integrating both of these raw materials still require further investigations. Some studies suggest that nutrient deficiency or excess influences the yeast metabolism to convert sugar into ethanol. In that regard, this work aims to explore the nutrients’ supplementation impacts on alcoholic fermentation of corn and sugarcane mixed wort. Results Corn hydrolysate and sugarcane syrup presented a Carbon/Nitrogen ratio above the recommended levels for ethanol production, 229.2 C:N ratio and 322.7 C:N ratio, respectively. The nutrients with the highest impact on alcoholic fermentation were determined using one-way ANOVA and Tukey statistical test. Thus, Nitrogen was the nutrient with the highest positive impact on yeast specific growth rate (49%), technological yield (35%) and productivity (32%). Organic acids ranged from 0.2–1.4 g.L− 1, glycerol was between 4–8 g.L− 1 and mannitol was under 0.05 g.L− 1. All were under the estimated ranges for alcoholic fermentation. Conclusions Among the nutrients studied, Manganese, Potassium and Nitrogen were the nutrients which significantly impacted the fermentative parameters for ethanol production. Although both feedstocks were poor in Nitrogen for alcoholic fermentations, Nitrogen concentration supplied (2,970mg/L) was enough to promote the yeast consumption of all total reducing sugars presented in the mixed wort. As a result, Nitrogen was the only nutrient which increased both yeast specific growth rate and ethanol production. Nevertheless, further studies should investigate an optimal Nitrogen concentration in order to decrease the glycerol and drive the yeast metabolism, preferentially, for ethanol rather than biomass production.

Background: Corn and sugarcane represent the world's most used feedstocks for ethanol production. Despite this, a single fermentation line integrating these both raw materials still require further investigations. Studies suggest that wort's nutrient deficiency or excess influences the yeast metabolism to convert sugar into ethanol. In that regard, this work aims to explore the nutrients’ supplementation impacts on alcoholic fermentation of mixed wort containing 80% v/v corn hydrolyzate and 20% v/v sugarcane syrup. Results: Corn hydrolyzate and sugarcane syrup presented a carbon/nitrogen ratio above the recommended levels for ethanol production, 229.2 C:N ratio and 322.7 C:N ratio, respectively. As a result, nitrogen was the nutrient with the highest positive impact on yeast specific growth rate (49%), technological yield (35%) and productivity (32%). However, its stoichiometric yield was 5% lower than the wort without supplementation. Finally, organic acids ranged from 0.2-1.4 g.L-1, glycerol was between 4-8 g.L-1 and mannitol was under 0.05 g.L-1. All were under the estimated ranges for alcoholic fermentation. Conclusions: All nutrients supplemented to the mixed wort increased the yeast specific growth rate, except calcium and iron. Moreover, Manganese, Cobalt and potassium impacted positively the stoichiometric yield and Nitrogen was the nutrient with highest technological yield. Finally, further studies should investigate an optimal nitrogen concentration in order to decrease the glycerol and drive the yeast metabolism, preferentially, for ethanol production rather than biomass production.