초록
<P><B>Abstract</B></P> <P>Lactic acid (LA) is an important chemical with various industrial applications. Non-food feedstock is commercially attractive for use in LA production; however, efficient LA fermentation from lignocellulosic biomass resulting in both high yield and titer faces technical obstacles. In this study, the thermophilic bacterium <I>Bacillus coagulans</I> LA204 demonstrated considerable ability to ferment glucose, xylose, and cellobiose to LA. Importantly, LA204 produces LA from several NaOH-pretreated agro stovers, with remarkably high yields through simultaneous saccharification and fermentation (SSF). A fed-batch SSF process conducted at 50°C and pH 6.0, using a cellulase concentration of 30FPU (filter paper unit)/g stover and 10g/L yeast extract in a 5-L bioreactor, was developed to produce LA from 14.4% (w/w) NaOH-pretreated non-sterile corn stover. LA titer, yield, and average productivity reached 97.59g/L, 0.68g/g stover, and 1.63g/L/h, respectively. This study presents a feasible process for lignocellulosic LA production from abundant agro stovers.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A thermophilic LA producing strain was identified as <I>B. coagulans</I> LA204. </LI> <LI> LA204 produces LA with high yield (0.52–0.75g/g straw) from several agro straws. </LI> <LI> LA yield reached 0.68g/g straw and the titer reached 97.59g/L in SSF process. </LI> <LI> A non-sterile feasible process was established to produce LA from corn straw. </LI> </UL> </P>