PURIFICATION AND CHARACTERIZATION OF AN EXTRACELLULAR AMYLASE FROM LACTOBACILLUS-PLANTARUM STRAIN A6

Extracellular amylase from Lactobacillus plantarum A6 was purified by fractionated precipitation with ammonium sulphate and by anion exchang e chromatography. The homogeneity of the purified fraction was tested by polyacrylamide gel electrophoresis and showed multiple amylase form s. A major form had an estimated molecular weight of 50 kDa. It was id entified as an alpha-amylase, with an optimum pH of 5.5, an optimum te mperature of 65-degrees-C and K(m) value of 2.38 g l-1 with soluble st arch substrate. The enzyme was inhibited by N-bromosuccinimide, iodine and acetic acid. The enzyme activation energy was 30.9 kJ mol-1.