Summary: | This study investigated the feasibility of producing L-lactic acid (LA) from dry corn stalk (DCS) that was pretreated by ensiling by an anaerobic microbial community consisting of <i>Bacillus coagulans</i>, <i>Lactobacillus fermentum</i>, and <i>Enterococcus durans</i>. After 28 days of ensiling, the LA and acetic acid content in the microsilage was 2.04 ± 0.08% and 0.38 ± 0.01%, respectively, and the pH was 4.47 ± 0.13. <i>Enterococcus and Lactobacillus</i> became the dominant microbiota during the ensiling process. Twenty-eight-day-old microsilage was then subjected to fermentation by <i>B. coagulans</i> to produce LA in a simultaneous saccharification and co-fermentation process. The enzymatic hydrolysis yield reached >96%. The maximal concentration of LA reached 18.54 ± 0.52 g/L with a substrate concentration of 5%, where the yield of LA was 0.31 ± 0.01 g/g DCS and the optical purity of the product LA was >97%. Anaerobic ensiling is viable for the pretreatment of biomass for the production of value-added chemicals.
|