Bacillus sp. IMD 435 produced a raw starch-digesting but non-raw starch-adsorbing alpha-amylase. Maximum amylase yield was achieved in a medium containing lactose (4%, w/v) as the carbon source and yeast extract (2%, w/v) as the nitrogen source. Although highest amylase yields were achieved with lactose, the biomass levels were notably less than those with starch or beta-cyclodextrin. The enzyme was purified in a single step using an alpha-cyclodextrin (CD) Sepharose 6B column, it had an M-r of 63 000 and displayed maximum activity at pH 6.0 and 65 degrees C. Glucose and maltose were released as the main end-products on hydrolysis of both soluble starch and raw corn starch.