Cellulase production by a new mutant strain of Trichoderma reesei MCG77

Conference · Sun Jan 01 04:00:00 EST 1978 · Biotechnol. Bioeng. Symp.; (United States)

OSTI ID:5860827

Gallo, B J; Andreotti, R; Roche, C; Ryu, D; Mandels, M

Productivity in a cellulase fermentation can be improved by optimization of media and fermentation conditions and by strain improvement, which enables us to alleviate or circumvent the genetic and metabolic controls that reduce or limit enzyme synthesis. T. reesei is the best organism to use for cellulase production because it produces high levels of a stable and complete cellulase complex. The wild strain produces little cellulase because of the restrictions placed on cellulase synthesis by genetic and metabolic controls. The mutant strains with enhanced cellulase productivity metabolic controls. The mutant strains with enhanced cellulase productivity AM 9414 and NG 14 are also subject to catabolite repression. With these mutants the best yields are attained when growth is good but restrained by substrate limitation or low pH. The results obtained in using new improved strains of T. reesei were discussed. High cellulase productivity was attained by using 6% two-roll milled cotton which contains about 80% fairly susceptible cellulose and about 20% residue that is very resistant to cellulase. The mutant strains grow rapidly on the susceptible portions of the cellulose, producing mostly biomass, and then continue hydrolyzing the resistant fraction of the cellulose with active enzyme production over a 14-day period, which results finally in broths containing up to 2% extracellular protein. Strain MCG 77 gives yields similar to the other enhanced mutant strains QM 9414 and NG 14 in regular cellulase fermentations. However, this strain grows rapidly on soluble substrates without subsequent restrictions in celllulase synthesis and has a faster rate of metabolism and enzyme production. 8 figures, 3 tables.

• Research Organization: Army Natick Research and Development Command, MA
• OSTI ID: 5860827
• Conference Information: Journal Name: Biotechnol. Bioeng. Symp.; (United States) Journal Volume: 8
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALDEHYDES
BIOCONVERSION
BIOSYNTHESIS
CARBOHYDRATES
CELLULASES
CELLULOSE
CHEMICAL REACTIONS
DECOMPOSITION
ENZYMES
FERMENTATION
FUNGI
GLUCOSE
HEXOSES
HYDROLASES
HYDROLYSIS
LYSIS
MONOSACCHARIDES
MUTANTS
ORGANIC COMPOUNDS
PLANTS
POLYSACCHARIDES
SACCHARIDES
SOLVOLYSIS
SYNTHESIS
TRICHODERMA
TRICHODERMA VIRIDE