Bismuth ferrite Fenton‐like pretreatment improves lactic acid production from corn stover without detoxification by Bacillus coagulans

Abstract

AbstractAgricultural stover is attractive as a raw material for lactic acid (LA) and polylactic acid (PLA) production because it does not compete with other food sources. The demand for PLA is extremely high. Pretreatment is an important step for LA production from agricultural stover. It improves the degradability of cellulose but always generates fermentation inhibitors. In this study, corn stover was pretreated with ammonia combined with a bismuth ferrite Fenton‐like process and then used for LA production through simultaneous enzymic saccharification and fermentation without detoxification treatment. The LA titer and yield were 92.35 ± 2.25 g L−1 and 0.62 g/g in fed batch fermentation under nonsterile conditions. Traces of formic acid were detected at the beginning of all experiments and disappeared during fermentation. Specific surface area and scanning electron microscopy observations of lignocellulose showed that there were many pore holes in pretreated corn stover fiber, which obviously improved the enzymatic hydrolysis efficiency. These results indicated that the bismuth ferrite Fenton‐like process is an economical and efficient pretreatment method that can improve the degradability of fiber, reduce inhibitors, and then achieve high LA production without detoxification and sterilization. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd