Studies On The Producing Kinetics Of β-Glucanase By Aspergillus Niger AS63 And The Enzyme's Properties

β-glucanase is an important industrial enzyme that may largely eliminate the negative effects caused by cereal β-glucan in brewing and feed industries. After mutated by mutagens such as UV and DES on the strain, a high-yielding β-glucanase Aspergillus niger AS63 was obtained. The productivity of β-glucanase by mutant AS63 was 45.6U/mL, 2.68 times higher than that of the initial stain W315. Subculture test indicated that the hereditary character of mutant AS63 was stable.In this dissertation, the medium composition and the fermentation conditions were investigated. The optimal medium composition, which was obtained through single factor experiments and orthogonal design experiments, was as follows (g/100mL): barley flour 5, soybean flour 3, (NH₄)₂SO₄ 0.3, K₂HPO₄ 0.1, MgSO₄ 0.06, FeSO₄ 0.001, CaCl₂ 0.5, Tween80 0.01 mL. The optimal conditions for fermentation were as follows: temperature 31℃, initial pH 6.0, 2.0mL seed culture containing 10⁸ cells/mL, 45mL medium in 250mL shaking flask, rotating rate 200rpm and culture time 55⁶5 hours. Based on the above experimental data, the...