The Studies on the Production of Antimicrobial Chitinase by Monascus sp. Using Shrimp and Crab shell as a Carbon source

• Main Authors: Haiao-wei-jen, 蕭惟仁
• Other Authors: San-Lang-Wang
• Format: Others
• Language: zh-TW
• Published: 2001
• Online Access: http://ndltd.ncl.edu.tw/handle/90404098088148923606

碩士 === 大葉大學 === 食品工程研究所 === 89 === This thesis is a study of the utilization of shrimp shell wastes by Monascus spp. to produce antifungal substance. The purification and characterization of fungicides were described. By resulting, we choose Monascus 31499 as the fungicide producer. That inhibitory activity（0.35U/ml）for Fusarium oxysporum was obtained when the strain was grown aerobically in a medium consisting of 1% shrimp shell wastes，0.l% K2HPO4 、0.05% MgS04 ．7H20 、0.001﹪FeSO4．7H2O 、0.3﹪NaNO3 、0.05﹪KCl 、0.l% yeast extract and 0.l% poly-peptone in 100ml medium at 25℃（pH 7）for 4 days. Besides Fusarium oxysporum ,it can also to fight the Lactobacillus acidophilus CCRC 10695、Lactobacillus delbrueckii subsp. lactis CCRC 10699 、Pseudomonas aeruginosa M1001 and Bacillus subtilus W113 .The fungicide was stable at pH from 6 to 8,but was not stable at 100℃. The culture supernatant was tested for hyphal growth, it caused abnormal hyphal swelling on the tip of Fusarium oxysporum. However, the optimum pH was 7 and optimum temperature was 40 degree C. The fungicide was purified from the culture supernatant of Monascus 31499 by ammonium sulfate fractionation and DEAE Sepharose CL-6B column chromatography. The purified enzyme was estimated to be 81kDa by SDS-PAGE have molecular weight.It showed chitinase activity and antifungal activity. It’s found to be an acidic protein with pI at 5.4. The optimum pH for enzymatic activity was approx.7 and the optimum temperature was 40 degree C. The enzyme was stabile at pH from 6 to 9 and 100℃ thermal stability for inhibition times less than 3 min. The activity of chtinase and protease was activated by Fe2+,but strongly inhibited by Hg2+and Acetone.