PURIFICATION AND CHARACTERIZATION OF AMYLASE PRODUCED FROM PROBIOTIC LACTOBACILLUS PLANTARUM CS FOR INDUSTRIAL APPLICATIONS

Abstract

Previous studies have demonstrated that probiotic Lactobacillus plantarum CS was able to generate an appreciable amount of extracellular amylase, hence the need to purify and characterize it. The aim of the study was to purify and characterize crude amylase from probiotic Lactobacillus plantarum CS for its industrial applications Three purification steps including ammonium sulphate precipitation, ion exchange chromatography on carboxymethyl sephadex and gel filtration on Sephadex G-75 were utilized. The homogeneity of the purified enzyme was confirmed using sodium deodocyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The purified amylase was characterized on different parameters including substrates hydrolyses, pH and temperature activity and stability profiles. The general purification elution profile revealed two different peaks of amylase activities with outstanding one having a molecular weight of 59.7kDa. Its purification fold was 4.0 with specific activity of 16.44U/mg protein and enzyme yield of 3%.  Temperature optimal activity and stability was at 400C and 7.5 for pH activity and stability. Mangenese (Mn2+) (135.17%), tween 80 (128.30%) and some food condiments garlic, thyme, ginger, and tumeric) significantly (p> 0.05) enhanced amylase activity (≥262.40%). However, selenium (Se4+) and hydrogen peroxide (H2O2) were observed to have greatest inhibiting effect (≥30.9%) on the enzyme. Substrate hydrolysis profiles showed that the amylase hydrolyzed all the test starchy substrates with the highest hydrolytic potential on indigenous sweet potato starch (Km value/ Vmax of 1.33mg/ml/ 7.89ml). The rate of hydrolysis of other test substrates had yam> rice>cassava>corn with km values ≤ 4.0mg/ml and Vmax ≤ 25ml.  The obtained results gave an insight that amylase produced from Lactobacillus plantarum CS met with the possessed properties suitable for any industrial application especially in food