High-titer L-lactic acid production from undetoxified corn stover hydrolysate by an inhibitor-tolerant Pediococcus acidilactici

ABSTRACT: In lignocellulosic biorefining, L-lactic acid fermentation is constrained by multiple factors: inhibitors generated during pretreatment and substrate deterioration of the enzymatic hydrolysate medium caused by autoclaving both inhibit microbial growth, resulting in low final product titers. In this study, a Pediococcus acidilactici strain with strong inhibitor tolerance, designated NHRI04, was obtained through stepwise adaptive evolution, and multi-omics analysis was employed to elucidate the mechanisms underlying its inhibitor tolerance. The results showed that NHRI04 could directly ferment undetoxified corn stover hydrolysate. Meanwhile, a pasteurization-based fermentation strategy was established to replace conventional autoclaving, effectively improving fermentation performance. After optimization of process parameters, a final L-lactic acid titer of 226.09 g/L was achieved, representing the highest lactic acid titer reported to date from corn stover hydrolysate by P. acidilactici at the 1.5 L scale. Cost analysis indicated that the combined effects of pasteurization and the omission of detoxification could reduce production costs by approximately $330 per ton of lactic acid, while saving 1.8 tons of corn and achieving a net carbon emission reduction of 1.83 t CO₂e per ton of lactic acid relative to the grain-based route.

ORGANISM(S): Pediococcus Acidilactici

SUBMITTER: Peiyong Qin  

PROVIDER: PXD085863 | iProX | Fri Oct 16 00:00:00 BST 2026

REPOSITORIES: iProX