Enhanced lactic acid production by Bacillus coagulans through simultaneous saccharification, biodetoxification, and fermentation

Abstract Agricultural straw is abundant worldwide, but efficient production of lactic acid from straw is still challenging. In this paper, Trichoderma viride R16 was cultivated using corncob as the substrate in a fed‐batch process, after which the enzymes from T. viride R16 broth were analyzed through protein mass spectrometry and used for lactic acid production. Dioxygenase activity was found in the T. viride R16 enzymes, and 0.2 g/L phenolics (vanillin, 4‐hydroxybenzaldehyde, syringaldehyde) was degraded during enzyme production. Lactic acid production and yield from NH 3 ‐H 2 O 2 pretreated and washed corncob were increased by more than 24% and total phenolics was significantly lower using T. viride R16 enzymes compared with commercial enzymes in batch and fed‐batch fermentation. These characteristics of T. viride R16 support industrial applications with efficient in situ detoxification of phenolic inhibitors without adding an extra step during lactic acid production from pretreated agricultural straw using simultaneous saccharification and fermentation. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd