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영어

Cellulose is the most abundant organic source of all plant materials. It is a linear biopolymer of glucose molecules, connected by β-1,4-glycosidic bonds. Cellulase is applicable to enzymatic hydrolysis of the bonds and produced from microorganism such as fungi and bacteria. In this study, cellulase was produced by Penicillium sp. KL1 in a 5-L laboratory scale fermentor. The culture medium for fermentation were consisted of 10g/L rice straw, 0.5 g/L yeast extract, 1 g/L KH2PO4 and 0.5 g/L CaCl2. Also, the effects of additives on nitrogen source (5 g/L) were examined using L-asparagine and corn steep liquor (CSL). The fermentation was performed at 30oC, 300 rpm in 5 L vessel during 10 days. After fermentation, the enzyme activities were measured by using filter paper(FP) and ρ-nitrophenyl-β- Dglucopyranoside( ρ-NPG) as substrates and determined by DNS method at 540 nm. Protein concentration was determined at 595 nm according to Bradford method using bovine serum albumin (BSA) as the standard. The enzyme activities were 1.33 U/ml of filter paper unit (FPU) and 1.51 U/ml of β-glucosidase unit (CBU) in the containing L-asparagine. Also, 1.10 U/ml of FPU and 1.40 U/ml of CBU were shown in the media containing CSL. Finally, the specific activity in the media containing L-asparagine was 34 FPU/mg-protein.