The study was focused on the isolation of the amylase producing bacteria belonging to the genus Bacillus and the optimization of several parameters such as cultural conditions and the nutritional requirements implicated in the production process. For the isolation of the amylase producing bacteria, six samples of soils and water were collected from the main geographic zones in North West of Algeria such as the river of Mekerra, Lake of Sidi Mohamed Benali, wastewater treatment plant of Sidi Bel abbes, field of potato in Ain Temouchent and the factory in Maghnia, where starchy wastes are submitted to natural fermentation. Fifty four bacterial strains of the genus Bacillus were isolated and selection of strains that produced most amount of amylase was determined on the basis of two criteria: the diameter of the zone of hydrolysis in solid medium and reducing sugar (DNS method in liquid medium). Furthermore, the most efficient strain was identified by the using of the API system as B. subtilis with a yield of 1,537 U/mL. Maximum production of amylase was obtained after optimization of the following parameters: starch concentration, nitrogen source, concentration of the inoculum and metal ions effect. Productivity was increased 6 times: 11,746 ± 0, 0028 U/mL in the optimized medium with the following composition: starch 5 g/L, gelatin 5 g/L, CaCl2; 0.2 g/L and 0.5 % v/v of inoculum.
