Pretreatment Optimization of Corn Stover with Subsequent Enzymatic Hydrolysis for Polyhydroxybutyrate (PHB) Production

Polyhydroxybutyrate (PHB) is considered a potential substitute for conventional, non-biodegradable petroleum-based plastics. However, high production cost has been major drawback to the commercialization of PHB. The use low-cost lignocellulosic agricultural residues such as corn stover, together with an effective pretreatment method, can reduce costs. In this study, optimization methods stover – namely, steam explosion and sequential explosion–dilute acid was done maximize concentration reducing sugars in hydrolysate obtained after enzymatic saccharification. Response surface methodology (RSM)-designed experiments showed that temperature had highest impact on sugar both methods. Optimum conditions were 220.9 °C 11.2 min residence time, yielding 9.67 g/L (64.50% yield) For pretreatment, 9.14 (60.93% produced from optimum 224.8 temperature, 144.2 dilute 43.8 reaction 5% w/v concentration. Dilute significantly decreased yield by 5.5%, probably due degradation sugars, making sufficient stover. More importantly, PHB using steam-exploded maximum 1.81 24 h bacterial fermentation. Therefore, proven producing sugar-rich hydrolysates production.