Optically pure lactic acid production from softwood-derived mannose by Pediococcus acidilactici

Softwood is of interest as a renewable carbon source for production of lactic acid. Softwood hydrolysate contains a high content of mannose. Lactic acid production from mannose by two modified strains, L-lactic acid producing Pediococcus acidilactici TY112 and D-lactic acid producing ZP26, was investigated in the current work. The two strains efficiently converted mannose to L- and D-lactate isomers with an optical purity exceeding 99 %, although the mannose utilization rates were lower than the glucose utilization rates. The mannose conversion to L- and Dlactic acids by P. acidilactici was also confirmed in dilute spruce hemicellulose hydrolysate. The present study provides important knowledge on utilization of the spectrum of fermentable sugars in softwood for future production of chiral lactic acid from lignocellulose feedstocks.

Automated summary

This study demonstrates that two modified strains efficiently utilize high mannose content in softwood hydrolysate to produce high-purity L and D-lactic acid. Despite lower mannose utilization rates compared to glucose, this research provides important insights for future production of chiral lactic acid from lignocellulosic feedstocks.