Lignocellulosic biomass is a promising feedstock for producing renewable chemicals and transportation fuels as petroleum substitutes. Fermentation of the cellulose in biomass in an SSF process requires that the properties of the microbial biocatalyst match the fungal cellulase activity optima for cost-effective production of products. Fermentation of the pentose sugars is an additional asset of an ideal biocatalyst. Thermotolerant Bacillus coagulans strains ferment pentose sugars completely to L(+)-lactic acid. The thermotolerant property of B. coagulans has been shown to also lower the cellulase requirement and associated cost in SSF of cellulose to lactic acid compared to lactic acid bacteria. However, the yield of lactic acid in sugar fermentations by B. coagulans never exceeded 55 g L^-1 even with pH control. In order to fully evaluate the metabolic potential of B. coagulans as an industrial L(+)-lactic acid producer, the potential inhibitory effect of lactic acid was minimized by trapping the lactic acid as calcium lactate. In fermentations of 120 g L^-1 of sugars in a medium supplemented with CaCO₃, the lactic acid yield was higher than 100 g L^-1.  In fed-batch fermentations with CaCO₃ in the medium, lactic acid titers reached as high as 180 g L^-1 and 160 g L^-1 from 200 g L^-1 of glucose and xylose, respectively. These results demonstrate that B. coagulans has the metabolic potential to ferment both hexoses and pentoses to L(+)-lactic acid at concentrations needed by the industry at 50-55 °C that would minimize contamination and reduce cooling costs.