Purification and Characterization of Beta-amylase

¿-amylase was purified and characterized from Bacillus subtilis isolated from fermented Parkia biglobosa seeds. Purification was achieved using ion exchange DEAE column and gel filtration (Sephadex G-200) chromatography. Effects of temperature; pH and production time on ¿-amylase production were investigated, while physicochemical characteristics of the purified enzyme were investigated. The optimum production of ¿-amylase was obtained at temperature, pH and time of 37oC, 7.0 and 24 h respectively. The results showed that purified ¿-amylase had more enzymatic activity than crude samples from Bacillus subtilis whereby the activity of crude enzyme was 3.21 mM/min/ml while the purified enzyme had an improved activity of 21.46 mM/min/ml. Optimum temperature and pH values of the purified amylase were found to be 50°C and pH 5.0, respectively. pH stability of the enzyme ranged from pH 4.0- 9.0. At pH 5.0 and 7.0 it retained 70% and 60% of its activity respectively after 5 h of incubation. Temperature stability ranged between 40oC and 70oC but most stable at 50oC retaining 64% of its activity after 1 h of incubation. The enzyme exhibited maximum activity on soluble starch and sucrose.