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Poster Presentation 6-09
Screening of Endoinulinase-producing Strain Chaetomium sp. C169 and Its Liquid Fermentation Conditions
Fumian Cui, Zhijun Hao, Bo Cui, Zhongxing Li
Institute of Microbiology, Chinese Academy of Sciences. 13 Yitiao Beiyijie, Zhongguancun, Haidian District, Beijing China 100080, PRC
Telephone: +8610 62554488; Fax: +8610 62560912; E-mail: fm_cui@zdl.net
Endoinulinase can be used for the preparation of inulooligosaccharides, which in turn could be used for food (multiplying bifido bacteria) and feed (improving feed efficiency).
Materials containing inulin hydrolyzed by enzymes may produce fructose or oligosaccharides, which can be used in the production of ultra high fructose syrups and inulooligosaccharides, as well as alcohol.
The endoinulinase-producing strain Chaetomium sp. C169 was isolated from a Jerusalem artichoke tuber contaminated by mold. The optimal liquid medium consisted of 1.5% Jerusalem artichoke tuber crude flour, 0.6% (NH4) 2HPO4 and 0.2% corn steep liquor. The optimal culture conditions in 250 mL flasks: initial pH of the medium, 7.5; temperature, 35ºC; shaking speed, 280 r/min; period, 3d. Enzyme activities of culture filtrate were 3.32 U/mL toward inulin and 0.04 U/mL toward sucrose, respectively, at pH 6.0 and 50ºC for 30 min. Ratio of inulinase activity to invertase activity was 80.3. The high I/S ratio suggested that Chaetomium sp. C169 produced mostly endoinulinase in the culture filtrate.
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