title: Enhanced cellulase production of the Trichoderma viride mutated by microwave and ultraviolet.
abstract: Cellulase-producing fungi Trichoderma viride were cultured and fermented on the solid-state wheat bran fermentation medium. The characteristics of its carboxymethyl cellulase (CMCase) in the condition of this solid-state fermentation were evaluated, and the optimum culture time, optimum pH and optimum temperature for CMCase activity of T. viride fermented in this solid state were 60h, 5.0 and 50 degrees C, respectively. Carboxymethyl cellulose sodium (CMC-Na) and Congo red were used to screen the strains that had stronger ability to produce enzymes. After the compound mutagenesis by microwave and ultraviolet, seven mutant strains (M-B1-M-B7) were selected and their CMCase activities were assayed. Five of them (M-B1, M-B2, M-B3, M-B5 and M-B7) had significantly stronger ability to produce enzymes than the normal wild type, and they were also very stable for a long period up to 9 generations to produce cellulase. Molecular studies showed that there were some base mutations in endoglucanase I (EG I) genes of mutants M-B1, M-B2, M-B3 and M-B5, but no change in M-B7, suggesting that some amino mutations in EG I proteins caused by base mutations could lead to enhanced cellulase production.
authors: Key Laboratory of Animal Epidemic Etiology & Immunological Prevention of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou 310029, PR China.
authors: Xing-hua
authors: XH
authors: Li
authors: Hua-jun
authors: HJ
authors: Yang
authors: Bhaskar
authors: B
authors: Roy
authors: Enoch Y
authors: EY
authors: Park
authors: Li-jun
authors: LJ
authors: Jiang
authors: Dan
authors: D
authors: Wang
authors: Yun-gen
authors: YG
authors: Miao
mesh_terms: D001483:Base Sequence; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism; D002480:Cellulase / Q000378:metabolism*; D003224:Congo Red / Q000378:metabolism; D003470:Culture Media / Q000737:chemistry; D004252:DNA Mutational Analysis; D004043:Dietary Fiber / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008872:Microwaves; D008969:Molecular Sequence Data; D020125:Mutation, Missense; D016415:Sequence Alignment; D013696:Temperature; D013997:Time Factors; D014242:Trichoderma / Q000201:enzymology* / Q000528:radiation effects*; D014466:Ultraviolet Rays
chemical_list: D003470:Culture Media; D004043:Dietary Fiber; D005656:Fungal Proteins; D003224:Congo Red; D002480:Cellulase; D002266:Carboxymethylcellulose Sodium