One-pot production of lactic acid from rice straw pretreated with ionic liquid

Production of platform chemicals has been advocated as a sustainable option to tackle the problems associated with agro-waste management. In this report, for the first time, efforts were made to effectively produce second generation lactic acid from rice straw pretreated with imidazolium ionic liquid [EMIM][OAc] and subsequently fermented with a promising Lactobacillus plantarum SKL-22 strain saccharified with a commercial cellulase enzyme. Medium optimization was carried out to enhance the lactic acid (LA) yield by response surface methodology. In a 5 L bioreactor, the process was further upscale, and a yield increment of 1.11% was observed. The process using rice straw as substrate led to a LA yield of 36.75 g/L from L. plantarum SKL-22 in a single pot bioprocess. Overall, the above finding has shown the ability of L. plantarum SKL-22 to produce LA from the hydrolysate of rice straw. This study presented a novel environmental-friendly method for LA production.

Automated summary

This study successfully produced second generation lactic acid from rice straw using imidazolium ionic liquid pretreatment, fermentation with Lactobacillus plantarum SKL-22 strain, and cellulase saccharification. By optimizing the medium, the lactic acid yield was increased, and scaling up in a 5 L bioreactor resulted in a 1.11% yield increment. Overall, the study demonstrated the potential of L. plantarum SKL-22 to produce lactic acid from rice straw hydrolysate in an environmentally friendly manner.