Inulinase-producing Marine Yeasts: Evaluation of their Diversity and Inulin Hydrolysis by Their Crude Enzymes

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• 作者：Lingmei Gao ; Zhenming Chi ; Jun Sheng ; Lin Wang ; Jing Li and Fang Gong
• 刊名：Microbial Ecology
• 出版年：2007
• 出版时间：November, 2007
• 年：2007
• 卷：54
• 期：4
• 页码：722-729
• 全文大小：234 KB
• 刊物类别：Biomedical and Life Sciences
• 刊物主题：Life Sciences
  Microbiology
  Ecology
  Geoecology and Natural Processes
  Nature Conservation
  
• 出版者：Springer New York
• ISSN：1432-184X

文摘

Total 427 yeast strains from seawater, sediments, mud of salterns, guts of the marine fish, and marine algae were obtained. After inulinase activity of the yeast cultures was estimated, we found that four strains (OUC1, G7a, OUC2, and G7a1) of the marine yeasts grown in the medium with inulin could secrete a large amount of inulinase into the medium. The results of routine identification and molecular methods show that they belong to Pichia guilliermondii OUC1, Cryptococcus aureus G7a, Yarrowia lipolytica OUC2, and Debaryomyces hansenii G7a1, respectively. The optimal pHs of inulinase activity produced by them were 6.0, 5.0, 5.0, and 5.0, respectively, while the optimal temperatures of inulinase activity produced by them were 60°, 50°, 60°, and 50°C, respectively. A large amount of monosaccharides and a trace amount of oligosaccharides were detected after the hydrolysis by the crude inulinase produced by P. guilliermondii OUC1, indicating that the crude inulinase had a high exoinulinase activity while a large amount of monosaccharides and oligosaccharides were detected after inulin hydrolysis by the crude inulinase produced both by C. aureus G7a and D. hansenii G7a1. However, no monosaccharides and disaccharides were detected after inulin hydrolysis by the crude inulinase produced by Y. lipolytica OUC2, suggesting that the crude inulinase had no exoinulinase activity.