Screening of lactic acid bacteria stable in ionic liquids and lignocellulosic by-products for bio-based lactic acid production

Lignocellulosic biomass are promising renewable resources for production of biofuels and platform chemicals. The present study encompasses the screening and isolation of lactic acid bacteria (LAB), stable in the presence of ionic liquids ([EMIM][OAc], [BMIM][MeSO4], and [BMIM][Cl]) and lignocellulosic inhibitors (HMF and furfural), and explores them for effective bio-based lactic acid production. Nineteen LAB producing isolates were identified based on their morphological, biochemical and 16S rRNA sequence analysis. Among these five LAB strains namely P. pentosaceus SKL-7, L. fallax SKL-15, L. plantarum SKL-19, L. paracasei SKL-21, and L. plantarum SKL-22 grew well in presence of ILs [EMIM][OAc], [BMIM][MeSO4], and [BMIM][Cl]. The L. plantarum SKL-22 exhibited relatively high tolerance with highest specific growth rates in presence of 0.5% and 1% [BMIM][MeSO4] and [BMIM][Cl]. Overall, L. plantarum SKL-22 produced reasonable good amount of lactic acid 34.26 g/l. It appears a promising strain for one-pot production of lactic acid from lignocellulosic biomass. © 2020 Elsevier Ltd