Improvement of Xylanase Activity of Aspergillus sp. by Physical and Chemical Mutagenesis

摘要

A xylan-degrading enzyme (endo U-1, 4 xylanase, EC 3.2.1.8) cleaves U-1, 4 glycosidic bond to produce xylose and is useful mainly in bio bleaching paper pulp, pharmaceutical and food industries. The purpose of the present investigation is to enhance xylanase production by subjecting indigenous xylanase producing strain Aspergillus niger to improvement by random mutagenesis by ultra-violet (UV) irradiation and N-methyl-N-nitrosourea (NMU) treatment. Mutants were screened as xylanase producers on the reddish zone of enzyme activity formation in PDA xylan agar plates. UV-12 mutant showed activities of 204.25 for submerged fermentation (Smf). UV-12 further mutated by NMU to produced NMU-10 mutant. Compared to wild strain, NMU-10 mutant produce 6.5 foldmore activities in Smf. Thus these findings have more impact on enzyme economy for biotechnological applications of microbial xylanase.