Cellulase production by Aspergillus niger under solid-state fermentation and applied in cellulosic ethanol production

• Main Authors: Yuan-chi Chen, 陳淵琪
• Other Authors: Kow-jen Duan
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/38aat6

碩士 === 大同大學 === 生物工程學系(所) === 102 === Wheat bran was used as substrate for Aspergillus niger TU-17 to produce cellulase. A circular bamboo steamer (9 cm ID) was used in the solid culturing process under the following culture condition: initial substrate pH 4.8; temperature 30°C; 40% moisture content, incubation time 6 days. 10% (v/w) of liquid seed culture was inoculated to the wheat bran. The maximum cellulase activity was 26 FPU/g-DS on the 4th day, and 刍-glucosidase 130 U/g-DS, CMCase 62.3 U/g-DS, xylanase 250.8 U/g-DS were concurrently obtained after 4-6 days of cultivation. The cellulase was extracted from the solid substrate and concentrated, the specific activity of FPU, 刍-glucosidase, CMCase, and xylanase were 17.7 U/mg, 87.8 U/mg, 42.1 U/mg, 169.5 U/mg respectively. The individual specific activity of cellulase in this study was compared to some commercial cellulases. The cellulase of this study was employed to produce ethanol from 脉-cellulose. This process was carried out by simultaneous saccharification and fermentation (SSF) using a thermotolerant Kluyveromyces marxianus at 40 牵C. A 112.5 FPU cellulase from Asp. niger was added to 100 ml medium with 7.5, 5, and 2.5 g 脉-cellulose (Sigma). The theoretical yields of ethanol production were 56, 42, 24 % from 2.5, 5.0, and 7.5% 脉-cellulose respectively. The supplement of commercial 刍-glucosidase increased the ethanol conversion yield to 82 % in 7.5% 脉-cellulose. The results indicated that cellulase produced from Asp. niger in this study can be used in ethanol production using the lignocellulose of agricultural wastes.