Effect of Various Physical and Chemical Factors on α-Amylase Activity Produced by the Marine Actinobacterium, Streptomyces Galilaeus

A total of 20 actinobacterial strains were isolated from the two estuarine fishes and examined for their amylase activity. Among them, one strain AS-10, which was identified as Streptomyces galilaeus showed higher amylase activity with lower biomass and it was taken for further study. The effect of various physical and chemical factors, such as pH, temperature, sodium chloride concentration, carbon compounds, nitrogen compounds and metal ions on the growth of S. galilaeus and amylase activity was studied. It was found that at pH 6, temperature 60 C, NaCl concentration 1-2%, carbon compound viz., lactose and nitrogen compound viz., L-phenylalanine and metal ion viz., Mn2 , the enzyme activity was maximum. The molecular weight of the amylase produced by the S. galilaeus was determined by the SDS-PAGE, which was 94 kDa