Lactobacillus casei was grown at 37 degrees C on sugarcane bagasse (5 g) soaked with cassava starch hydrolysate (final moistening volume 34 ml) containing 3 g reducing sugar in a solid-state condition. The maximum yield of L-lactic acid after various process optimisations was 2.9 g/5 g initial substrate corresponding to 97% conversion of sugar to lactic acid with initial substrate moisture of 72%.