摘要：The aim of the present study was to produce mutants from Klebsiella edwardsii capable of producing large quantity of mannanase . Mutants of K. edwardsii were generated by subjecting the cell culture to nitrous acid (0.1 M sodium nit rite in phosphate buffer ) . The mutants and the wild type were screened quantitatively for mannanase synthesis in basal medium containing Locust Bean Gum (LBG) as inducer. Twent y mutants were generated and screened for mannanase production in comparison with the wild t ype in submerged state fermentation. The isolated mutants were screened in comparison with wild type for the isolation of carbon catabolite activation mutants in th e presence of 0.1, 0.5 and 1.0% ( w/v ) glucose as energy source. The entire mutant strains showed higher mannanase activities than the wild type, with the highest mannanase activity lied on mutant designated HN02. The supplementation of 0.1% ( w/v ) glucose in the fermentation media caused repression of mannanase synthesis in 60% of the mutants, while onl y 20% of the mutant exhibited higher mannanase activities when compared with wild type. The supplementation of 0.5 and 1.0% ( w/v ) glucose in the fer mentation media enhanced mannanase production in 80% and 60% of the mutants respectively when compared with the wild type.
