College of Agriculture / University of Baghdad


This research is conducted at the College of Agriculture, University of Baghdad in 2004 where the α – amylase enzyme, which is produced by Bacillus licheniformis R5 under optimum conditions, is purified by several steps which includ adsorption to Starch and precipitation by Ammonium Sulphate at 40 – 80% saturation, where the effectiveness of the enzyme, also the quality and effectiveness is 14 016 units / ml and 114 885 units / mg , respectively. The number of purification times that could be achieved is 11.8 times and developed to 45.2%.
Gel filtration using the Sephacryl S- 200 column was used for purification. The purification folds and the yield of the enzyme at the end of these steps are 40.39 times and 35.20% respectively. The products obtained at various stages of the Starch hydrolysis by the enzyme performed by Thin – Layer Chromatography, showed that at the early steps of the reaction (after 20 min) only with the Oligosaccharides are appear while Glucose and Maltose, as the major products of the hydrolysis, are detectable after 30 min of the reaction time.