Showing papers on "Trichoderma reesei published in 1978"
01 Jan 1978
TL;DR: 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.
Abstract: 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,more » 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.« less
31 citations
TL;DR: A simple adsorption and elution of the trehalase of Trichoderma reesei on bentonite increased the specific activity 70-80 times, with a recovery of 90%.
Abstract: A simple adsorption and elution of the trehalase of Trichoderma reesei on bentonite increased the specific activity 70–80 times, with a recovery of 90%. This α,α-trehalase has an optimum pH of 4.4,...
12 citations
TL;DR: Recent work on production of cellulolytic enzymes and on enzymatic degradation of cellulose is described and Xylitol and furfural process wastes have been shown to be suitable substrates for cellulase, requiring little or no costly pretreatment.
Abstract: Production of cellulases and enzymatic cleavage of cellulose. Recent work on production of cellulolytic enzymes and on enzymatic degradation of cellulose is described. For optimum enzyme production by Trichoderma reesei under carefully balanced growth conditions, cellulose levels as high as 2% may be employed. Nitrogen deficit may be economically avoided by adding organic nitrogen in the form of distiller's spent grain and dried ground T. reesei cell mass. Semicontinuous production has been shown to offer further special advantages. Cellulase activity may be directly monitored automatically in a computer-controlled pilot fermentation system. Xylitol and furfural process wastes have been shown to be suitable substrates for cellulase, requiring little or no costly pretreatment. The rate of cellulose hydrolysis is considerably increased by combined use of T. reesei and cellobiase active microorganisms such as Aspergillus phoenicia.
6 citations