title: Strain improvement of Trichoderma reesei Rut C-30 for increased cellulase production.
abstract: The strain of Trichoderma reesei Rut C-30 was subjected to mutation after treatment with N-methyl-N'-nitro-N-nitrosoguanidine (NG) for 6 h followed by UV irradiation for 15 min. Successive mutants showed enhanced cellulase production, clear hydrolysis zone and rapid growth on Avicel-containing plate. Particularly, the mutant NU-6 showed approximately two-fold increases in activity of both FPA and CMCase in shake flask culture when grown on basal medium containing peptone (1%) and wheat bran (1%). The enzyme production was further optimized using eight different media. When a mixture of lactose and yeast cream was used as cellulase inducer, the mutant NU-6 yielded the highest enzyme and cell production with a FPase activity of 6.2 U ml(-1), a CMCase activity of 54.2 U ml(-1), a β-glucosidase activity of 0.39 U ml(-1), and a fungal biomass of 12.6 mg ml(-1). It deserved noting that the mutant NU-6 also secreted large amounts of xylanases (291.3 U ml(-1)). These results suggested that NU-6 should be an attractive producer for both cellulose and xylanase production.
authors.affiliation: Institute of Animal Nutrition, Sichuan Agricultural University, Yaan, Sichuan, 625 014 P. R. China  ; Key Laboratory of Animal Disease-Resistance Nutrition, Ministry of Education, Yaan, Sichuan, China.
authors.forename: He
authors.initials: H
authors.lastname: Jun
authors.forename: Yu
authors.initials: Y
authors.lastname: Bing
authors.forename: Zhang
authors.initials: Z
authors.lastname: Keying
authors.forename: Ding
authors.initials: D
authors.lastname: Xuemei
authors.forename: Chen
authors.initials: C
authors.lastname: Daiwen
keywords: Cellulase; Fermentation; NTG and ultraviolet mutation; Trichoderma reesei