title: Production and properties of beta-mannanase by free and immobilized cells of Aspergillus oryzae NRRL 3488.
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.
authors.affiliation: Department of Natural and Microbial Products Chemistry, National Research Centre, Dokki, Cairo, Egypt.
authors.forename: A M
authors.initials: AM
authors.lastname: Hashem
authors.forename: A M
authors.initials: AM
authors.lastname: Ismail
authors.forename: M A
authors.initials: MA
authors.lastname: El-Refai
authors.forename: A F
authors.initials: AF
authors.lastname: Abdel-Fattah
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology*; D018914:Cells, Immobilized; D005685:Galactans; D008351:Mannans; D008361:Mannosidases / Q000096:biosynthesis* / Q000378:metabolism*; D053149:Plant Gums; D011134:Polysaccharides / Q000378:metabolism; D044902:beta-Mannosidase
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011134:Polysaccharides; C007916:hemicellulose; D008361:Mannosidases; D044902:beta-Mannosidase; C017471:locust bean gum