Sorbitol production from a mixture of sugarcane bagasse and cassava pulp hydrolysates using thermotolerant Zymomonas mobilis TISTR548

The sorbitol production capability of different thermotolerant strains of Zymomonas mobilis and the optimization conditions for sorbitol production using sugarcane bagasse hydrolysate (SBH) and cassava pulp hydrolysate (CPH) as feedstocks were investigated. Among the different bacterial strains and combinations of SBH and CPH, the thermotolerant Z. mobilis TISTR548 and a mixture of SBH and CPH at a ratio of 0.50:0.50 provided the highest sorbitol concentration at 37 °C. A screening of the environmental factors influencing sorbitol production by Z. mobilis TISTR548 using the Plackett-Burman design (PBD) revealed three significant independent variables, i.e., CaCl 2 , NaCl, and pH, which positively affected sorbitol production using a mixture of SBH and CPH as substrate. The response surface methodology (RSM) based on the central composite design (CCD) resulted in the optimum CaCl 2 concentration of 2.47 g/L, a NaCl concentration of 0.08 g/L, and a pH of 6.49, yielding the maximum sorbitol concentration of 5.89 g/L, which was approximately 2.0-fold higher than that of the non-optimal conditions. This finding suggested that the bioconversion of lignocellulosic biomasses into sorbitol through microbial fermentation is another platform for sustainable industrial high-value bioproducts . • Sorbitol production from a mixture of sugarcane bagasse and cassava pulp hydrolysates. • High-temperature sorbitol fermentation using thermotolerant Zymomonas mobilis. • Optimization conditions for sorbitol production using a statistical experimental model.