RESUMEN
Studies on the alpha -amylase synthesis was carried out with a moderately thermophilic, facultatively anaerobic Bacillus sp, isolated from soil samples. The cells were cultivated in a complex medium containing soluble starch or maltose as carbon source. The levels of the alpha -amylaseactivity detected in culture supernatants varied greatly with the type of carbon source used. Maltose, soluble starch and citrate stimulated alpha -amylaseformation. Addition of exogenous glucose repressed formation of alpha -amylase, demonstrating that a classical glucose effect was operative in this organism. The concentration of yeast extract was found to be important factor in the alpha -amylase synthesis bythe isolate.The activity of the enzyme increased between 2 and 5 g/L yeast extract concentration and then fell very rapidly beyond this point. The best concentration of peptone to alpha-amylase formation was found to be around 10g/L