Screening of cellulase producing strains and its enzyme application

• Main Authors: Mu-Ting Wu, 吳牧庭
• Other Authors: Chi-Lung Chang
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/36462792896603266395

碩士 === 明道大學 === 材料科學與工程學系碩士班 === 99 === Complete hydrolysis of fiber yields the easily fermented glucose, which were the source of energy for animals. Non-ruminant animals can not secrete the cellulose result in the utilization of the fiber is restricted. The purpose of this study was examined the cellulose-producting strains which are isolated from the termites, the rumen liquid of dairy cows, and ruminants waste through the enzyme radial diffusion method. One of the best strain R3 isolsted from the rumen liquid of dairy cows according to the fiber degradability. After the 7 day cultivation period, the carboxymethyl cellulase activity of R3 under the optimal cultural condition (37℃ and pH 5.0) was 356 mU/ml. The 16S rDNA of R3 was extracted, amplified, sequenced and compared with the data base of NCBI GenBank was finally identified as Bacillus sp. The wheat bran was used as substrate in solid fermentation and in vitro fiber degradation determination to evaluate the fiber degradability. The R3 broth from 7-day cultivation was blended with the wheat bran in the ratio in 0.75 ml/g for the solid fermentation. After the 5-day fermentation period, the neutral detergent fiber (NDF) degradability of wheat bran was 48.2%. In the in vitro fiber degradation determination, the nylon bag contained wheat bran was soaked into the suspension which was collected from the 7-day cultivation by centrifugation. The dry matter (DM) and NDF degradability of wheat bran was 24.8 and 34.7%, respectively. Overall, Bacillus sp. R3 has the ability to produce the cellulase to hydrolyze the cellulose and improve the nutrient value of feedstuffs.