Influence of Environmental Factors on Extracellular Amylase from Bacillus subtilis and Its Kinetic Properties

Amylase is an important industrial enzyme used in various food and textile industries Bacillus species are observed to be potential producers of various extracellular enzymes including amylase The present investigation was earned out with an objective to find out the optimum substrate concentration, temperature, (p)H, effect of chemical reagents like EDTA and Mg(++) ions on amylase production by B subtillis isolated from the soil sample of the field of Central Farm, OUAT, Bhubaneswar The amylase activity of the isolate was found to be 68 376 +/- 1 5 Huggins and Russel unit/mg protein/30-min at 40 degrees C The effect of substrate concentration on the enzyme activity was observed to be Km-2 85mg and Vmax 250 HR unit/mg protein/30 minute The optimum temperature for amylase activity was 60 degrees C The effect of time study indicates a first order rate constant K as 8 70* 10(5) sec(1) at 40 minutes The effect of divalent cation Mg(++) on amylase activity of B subtilis as also studied and the percentage of inhibition was found to be 12 18%,36 57%,48 88% and 57 14% at 1 mM, 2mM, 3mM and 5 mM respectively EDTA accelerates the rate of enzyme activity at 1mM and 2mM concentration and from 3 to 5 mM concentration, it inhibits enzyme activity The amylase production also vanes at different pH in starch agar medium At lower pH the activity is totally inhibited and it Increases gradually with increase in pH, the optimum being pH 7 0