Determination of Optimum Solid Culture Conditions for the Raw Sago Starch-Digesting Amylase Production by Penicillium brunneum.

Abstract

With the present need for raw sago starch-digesting enzyme preparation, fungi obtained from sago palm tree and sago starch processing sites were screened for production of the amylase. We selected Penicillium brunneum as a source of raw starch-digesting amylase. This fungus was cultivated on a solid culture medium containing 42% wheat bran, 4% sago starch, 4% rice hull and 50% water at 30°C for 7 days. The extract of that culture was found to have ability to digest raw starch granules. Optimum solid culture conditions to produce the enzyme were studied by cultivating this strain at various incubation conditions. Optimum initial pH and optimum temperature were 4.5 and 33°C, respectively. The enzyme produced in the culture medium consisting of 56% wheat bran, 4% sago starch and 40% water, had higher raw sago starch-digestive activity. Addition of 20 mM of CaCl2 or 20 mM of NiC12 and addition of 0.02 % of yeast extract in the culture medium was effective in increasing the production of the enzyme to digest raw sago starch. The culture could be harvested after 6 days cultivation.