초록
Wheat bran, among various agro industrial by products, screened for the production of polygalacturonase (PG) in solid-state fermentation of Aspergillus sojae mutant strain, was found to be the most suitable substrate without the addition of any nutritive or inducing supplement. It was further characterized for its physicochemical composition and particle size distribution. The process conditions that favored the PG production using this substrate were determined as; 10<SUP>7</SUP> spore/g substrate inoculum concentration, 4 days of fermentation, 37<SUP>o</SUP>C of incubation temperature, 62% initial moisture content, water as the moistening agent, 100-250μm particle size of wheat bran, 3 times/day agitation and spore solution as the inoculum type which resulted into maximum PG activity of 535.4U/g substrate. Overall, this optimization process resulted in 7.3 and 3.9 fold of significant enhancement in the PG activity and productivity, respectively.