Study of bioethanol production from sorghum residue by optimization of pre-treatment and enzymatic degradation: Co-culturing of Saccharomyces cerevisiae and Pichia stipitis as fermentation approach

The co-utilization of pentose and hexose in lignocellulosic biomass hydrolysate is the core for economically fermentative production of the second-generation bioethanol as a sustainable biofuel candidate. In this research, the production of bioethanol by co-culturing S. cerevisiae (MTCC174) and P. stipitis (NCIM 3497) with the SHF (separate hydrolysis and fermentation) process was reported. Enzymatic the saccharification process for fermentable sugars is induced by NaOH pre-treated SSR, as evidenced by the data. The optimal Box-Behnken Design parameters for pre-treated and hydrolyzed SSR were reported with 2 % concentration of NaOH, 1 mm with particle size, and 50 min duration were explored and showed a maximum cellulose concentration of 62.7 % as a response. The variables investigated in the model for hydrolysis found the maximal concentration of reducing sugar of 42.7 ± 2.117 mg/g, at ∼50℃ with 1:2 enzymes loading at a time of ∼72hrs. The physical and structural analysis can be done with FTIR, XRD, and FESEM techniques. The highest concentration of bioethanol of 16.8 g/L was attained in 72hrs fermentation time. The study infers that SHF has great potential for producing high-titer ethanol commercially and supports waste-to-energy strategies.