In this study, microbial growth kinetics and modeling of alcohols production using Saccharomyces cerevisiae were evaluated using different hydrolysates in a single pot (batch) system. Mixed agro-waste hydrolysates from different pre-treatment methods, i.e., N. mirabilis/CP and HWP/DAP/CP, were used as the sole nutrient source in the fermentations used to produce the alcohols of interest. The maximum Saccharomyces cerevisiae concentration of 1.47 CFU/mL (×1010) was observed with HWP/DAP/CP hydrolysates, with a relative difference of 21.1% when compared to the N. mirabilis/CP cultures; the product yield based on biomass generation was relatively (20.2%) higher for the N. mirabilis/CP cultures. For the total residual phenolic compounds (TRPCs) generation, a relative difference (24.6%) between N. mirabilis/CP and HWP/DAP/CP pre-treatment systems was observed, suggesting that N. mirabilis/CP generates lower inhibition by-products. This was further evidenced by the lowest substrate utilization rate (3.3 × 10−4 g/(L·h)) for the N. mirabilis/CP cultures while achieving relatively similar product formation rates to those observed for the HWP/DAP/CP. A better correlation (R2 = 0.94) was obtained when predicting substrate utilization for the N. mirabilis/CP cultures. Generally, the pre-treatment of mixed agro-waste using N. mirabilis/CP seemed appropriate for producing hydrolysates which Saccharomyces cerevisiae can effectively use for alcohol production in the biorefinery industry.
Heterologous production of raspberry ketone in the wine yeast Saccharomyces cerevisiae via pathway engineering and synthetic enzyme fusion
