Production and properties of beta-mannanase by free and immobilized cells of Aspergillus oryzae NRRL 3488 |
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Authors: | Hashem A M Ismail A M El-Refai M A Abdel-Fattah A F |
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Institution: | Department of Natural and Microbial Products Chemistry, National Research Centre, Dokki, Cairo, Egypt. |
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Abstract: | Seven fungi were tested for production of mannanases. The highest mannanase activities were produced by Aspergillus oryzae NRRL 3488 after 7 days in static cultures. Mannanases were induced by gum locust bean (1.0%). The highest mannanase activity was produced when a mixture of peptone, urea and ammonium sulphate was used as nitrogen source. Zn2+ or Co2+ favoured enzyme production. The immobilized cells on Ca-alginate and agar were able to produce beta-mannanase for four runs with a slight decrease in the activity. The optimum temperature for enzyme reaction was 50-55 degrees C at pH 6.0. In the absence of substrate the enzyme was thermostable retaining 75% activity for 1 h at 50 degrees C, and 68% activity for 1 h at 60 degrees C. |
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