Font Size: a A A

Research On Fermentation Of Xylanase Producing Strain Trichoderma Reesei

Posted on:2009-01-13Degree:MasterType:Thesis
Country:ChinaCandidate:Y WeiFull Text:PDF
GTID:2121360272956787Subject:Sugar works
Abstract/Summary:PDF Full Text Request
The xylanase production was investigated with submerged fermentation by Trichoderma reesei. SAS RSREG (Response Surface Regression) were employed to evaluate the effects of factors (carbon/nitrogen source, initial pH, cultural time, and etc) on xylanase production. The optimum constitute of culture medium was beef extract: peptone: corncob is 1:0.16:4.5, corncobs: glucose is 1:0.14. Xylanase activity reached 288U/mL under the optimized conditions (30℃, 63 h, 200 r·min-1).The feasibility of the regression models was also carried out, and minor xylanase activity was detected during the first 12 h, and a significant increase in xylanase activity was observed after 24 h cultivation. The xylanase activity reached maximum after 63 hours cultivation, and a decrease in xylanase activity was observed after that time. A slight decrease in the pH value during the first 24 h and the pH value reached 8 at the 96th hour of cultivation.According to the request of practical applications, the article also studied the immobilization technique, which used glutaraldehyde to immobilized xylanase without any carriers. The best conditions for immobilization were optimized as follows: The concentration of glutaraldehyde is 1%, the best immobilized time is 90min.The immobilized enzymes were systematically characterized in terms of their catalytic activity, thermal and pH stability. Compared with the free enzyme, the optimum pH of immobilized xylanase from the Trichoderma reesei shifted from 5.5 to 6.0, and was stable at pH 5.0~8.0. The optimum temperature of the immobilized enzyme increased from 45℃to 50℃. The thermalstability of the immobilized enzyme also increased significantly.The immobilized xylanase was used in the hydrolysis of corncob. The optimal hydrolysis conditions for substrates were investigated. Results showed that: The rational substrate concentration was 4% and the proper amount of xylanase was 200U/g substrate for the enzymatic hydrolysis of corncob.
Keywords/Search Tags:Trichoderma reesei, Xylanase, optimize, immobilization, property
PDF Full Text Request
Related items