Maltodextrins and hydrolysates of rice and corn flour of varying dextrose equivalents (DE) have been used as a carbon source for alpha-amylase enzyme production by Bacillus sp. TCRDC-25A. The rate and total enzyme production was higher in maltodextrin media than in cornstarch. The enzyme production increased with increase in DE up to 45%. The maximum enzyme production of 2390, 2450, and 2510 DUN/mL was obtained in cornstarch maltodextrins, and hydrolysates of corn and rice flours, respectively, in a bench-scale reactor in 40 h.