Production of Cellulose and Xylan Degrading Enzymes by Aspergillus fumigatus Fresenius No. 4-45-IF Using Agricultural Wastes as Substrate.

Abstract

A comparative study was made on the production of cellulose and xylan degrading enzymes by Aspergillus fumigatus Fresenius No. 4-45-IF using solid substrate cultivation on rice straw, bagasse, corncob. cornhull or wheat bran. The results indicated that rice straw served as the best substrate. Initial moisture content of rice straw played an important factor on the enzyme production. Maximum enzyme activities were obtained when the culture was grown at level the of 81% initial moisture content. Addition NH₄NO₃ to the culture medium significantly enhanced the formation of beta-xylanase, beta-xylosidase and filter paper activity (FPase), but slightly increased the activity of beta-glucosidase and carboxymethylcellulase (CMCase). When the culture was grown at 40 degree C for 4 days on medium containing 5 g rice straw supplemented with 0.2 g NH₄NO₃ and 0.001 g yeast extract at 81% initial moisture content, 19.4, 24.6, 15.7, 540 and 2.3 units/g dried solid of FPase, CMCase, beta-glucosidase, beta-xylanase and beta-xylosidase were obtained, respectively. Addition of 2 mg sodium pentachlorophenate to the culture medium retarded growth and sporulation, and resulted in a decrease of all enzyme activities except beta-glucosidase.