Print ISSN: 2077-5822

Online ISSN: 2618-1479

Keywords : Bacillus licheniformis R


Purification of α- Amylase Produced from of Bacillus Licheniformis R5

Rana Abdullah Hussein; Mohammed O.Muhyaddin

Al-Qadisiyah Journal For Agriculture Sciences, 2016, Volume 6, Issue 2, Pages 108-116
DOI: 10.33794/qjas.2016.115296

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.

Characterization of α- Amylase Produced from a Local Isolate of Bacillus licheniformis R5

Rana Abdullah Hussein; Mohammed O.Muhyaddin

Al-Qadisiyah Journal For Agriculture Sciences, 2016, Volume 6, Issue 2, Pages 34-48
DOI: 10.33794/qjas.2016.115239

This research is conducted at the College of Agriculture, University of Baghdad in 2004. The characterization of the purified enzyme shows that the molecular weight of the enzyme produced from the bacteria is 56.000 Daltons as it was determined by gel filtration on Sephacryl S- 200 column and the pH of the enzyme activity is 8.0 but the enzyme is more stable at pH range between 7.0 – 9.0, also the optimum temperature of the enzyme activity was 50°C at the optimum pH stability. The activation energy of the converted substrate (starch) of products was 17.500 cal mole while the activation energy of the denaturized enzyme is 64.000 cal mole.
The Kinetic studies show that the Michaels constant (Km) values of the enzyme using starch, glycogen and amylose as substrates are 0.44 mM, 0.43 mM and 0.28 mM respectively, revealing that the enzyme has a highest affinity to amylose in comparison with starch and glycogen , It was also found that the addition of calcium chloride to the reaction mixture increase the enzyme activity by 138.8% (Conc. of 0.6 mM) , also by measuring the thermo stability of the enzyme in the presence of calcium chloride with a concentration of (0.6 mM and 1.0mM) at (70 – 80)°C , the enzyme has kept its total activity at 70°C and 95.3% of its activity in the presence of 0.6 mM of calcium chloride and 100% in the presence of 1.0 mM at 80°C .