Acid stable α-amylase from Pseudomonas balearica VITPS19—Production, purification and characterization

In the present study, α-amylase from Pseudomonas balearica VITPS19 isolated from Kolathur, Tamil Nadu, India was studied. Initially, one factor at a time (OFAT) approach was used to optimize the medium parameters like pH, temperature, carbon and nitrogen sources and the presence of metal ions to enhance the amylase activity. After the optimization, 6.5-fold increase in the enzyme production was observed. Enzyme purification was carried out in three stages. The molecular weight of purified α-amylase was estimated to be 47 kDa.The optimum activity for the purified enzyme was observed at pH 6 in 0.1 M phosphate buffer at 25 ± 2 °C and the activity is enhanced in the presence of ions like Mn(2+), Mo(6+), Na(+), Mg(2+)and Zn(2+) and was inhibited in the presence of Hg(2+) ions. Compounds such as Sodium dodecyl sulfate (SDS), Ethylenediaminetetraacetic acid (EDTA), urea and β- mercaptoethanol reduced the amylase activity. The K(m) and V(max) of the α-amylase was estimated to be 45.23 mM and 20.83 U/mL, respectively.