Co-fermentation exploiting glucose and xylose utilizing thermotolerant S. cerevisiae of highly lignified biomass for biofuel production: Statistical optimization and kinetic models

Abstract

The present study assesses the potential of co-fermentation for the enhanced production of biofuels from a highly lignified biomass, Viz., Pomegranate Peel (PP) and Mosambi Peel (PP). The simultaneous saccharification and co-fermentation (SScF) on brewer's yeast Saccharomyces cerevisiae and modified strain S. cerevisiae XUSE were used for the ethanol production using RSM. The Box-Behnken design (BBD) model was used to execute 15 runs with independent factors of initial pH (5.5, 6.5, 7.5), yeast concentration (4%, 5% and 6%v/v), and co-culture yeast concentration (4%, 5% and 6%v/v). The highest bioethanol production was achieved by PP (35.460 ± 0.32 g/L) and MP (25.630 ± 0.40 g/L) on optimal variables of pH 6.5, with yeast concentration (5% v/v) and co-culture yeast concentration (5% v/v) for 120 hrs duration. Furthermore, the kinetic of logistic and modified Gompertz model analyzed the lag phase of PP and MP was 7.9 and 7.15 h, for which maximum bioethanol production (EtOH max-Pm) reported for PP (38.62 g/L) and MP (29.21 g/L), respectively. The study infers that SScF has great potential for producing high-titer ethanol commercially and supports waste-to-energy strategies.