Statistical Optimization and Partial Characterization of Amylases Produced by Halotolerant Penicillium Sp

The production of extracellular amylase by the halotolerant fungus Penicillium sp. was statistically optimized in a submerged cultivation. Maximum enzyme production was obtained after two days of incubation in a medium containing 10% (w/v) NaCl, in addition to MgSO .7H O 1% and 1% (w/v) of 4 2 starch. The optimum pH for growth and enzyme production was 4. Partial characterization of the crude enzyme revealed the presence of two enzymes with pH-optima at 9 and 11. Further more, the optimum temperature was 30°C at pH 11 and from 30°C to 90°C at pH value of 9. The two enzymes were stable in wide pH range with the maximum stability at pH 9 to 11 after 5 days and at temperature range of 40-60°C. Different starchy materials (barley grains, wheat grains, wheat bran, crushed wheat grains, birds feed grains, maize meal and wheat meal) were tested as substrates for amylase production in solid state fermentation (SSF). The highest enzyme production was obtained in presence of maize meal after 6 days of incubation at 30°C when enzyme assayed at pH 11.