Introduction
abstract
Jerusalem artichoke is a low-requirement crop, which does not interfere with food chain, and is a promising
carbon source for industrial fermentation. Microbial conversion of such a renewable raw material to
useful products, such as lactic acid, is an important objective in industrial biotechnology. In this study,
high-optical-purity L-lactate was efficiently produced from the hydrolysates of Jerusalem artichoke powder
by a thermophilic bacterium, Bacillus coagulans XZL4. High L-lactate production (134 g l1) was
obtained using 267 g l1 Jerusalem artichoke powder (total reducing sugars of 140 g l1) and 10 g l1 of
corn steep powder in fed-batch fermentation, with an average productivity of 2.5 g l1 h1 and a yield
of 0.96 g g1 reducing sugars. The final product optical purity is 99%, which meets the requirement of lactic
acid polymerization. Our study represents a cost-effective and promising method for polymer-grade
L-lactate production using a cheap raw bio-resource.