Trichoderma, cellulase system

Production of Trichoderma reesei Cellulase System with High Hydrofytic Potential by Solid-State Fermentation... 

Table V. Composition of Cellulase System Produced on Pro-cell with Trichoderma reesei QMY-1 in SSF...

Component enzymes of the cellulase system have been purified from several microbial species (1-13), among which mutants of the imperfect fungus Trichoderma provide the highest levels of extracellular enzyme activity (14). From this organism have been purified / -glucosi-dases (EC 3.2.1.21), endo-l,4-/ -D-glucanases (EC 3.2.1.4) and 1,4-/ -d-... 

Capitalizing on this metabolic difference between higher forms of life and micro-organisms is the basis for this research approach to wood protection. Compounds are available which inhibit the cellulase enzyme systems however, their specificity has not been determined. Mandels and Reese (21,22) found that the extracts from the immature fruit of persimmon or the extract from leaves of bayberry were very effective inhibitors of the cellulase system. At concentration levels of. 00005 and. 00018%, respectively, these two extracts inhibited the cellulase enzymes isolated from Trichoderma viride. It is not known what the active component(s) are in these two extracts. 

Claeyssens, M., van Tilbeurgh, H., Tomme, R, Wood, T.M., and McCrae, S. I., Fungal cellulase systems Comparison of the specificities of the cellobiohydrolases isolated from Penicillium pinophilum and Trichoderma reesei. Biochem. J. 1989,261, 819-826. 

The second step in the direct ethanol process is that of enzyme production. The Gulf process utilizes a mutant strain of Trichoderma reesei, grown continuously to produce a complete cellulase system. The residence time is 48 hours. Enzyme production begins on a spore plate with subsequent scale-up to the enzyme production vessel size to be used. Our pilot plant facility has 300-gal enzyme reactors. 

The third step in the direct ethanol process is to produce the yeast necessary for converting the glucose to ethanol. Varieties of organisms have been screened for compatibility with the Trichoderma reese/cellulase system. The optimum temperature for the cellulase system is 45 to 50 C. Most yeasts have a temperature optima less than that, e.g., 30 to 35 C. We have tested a variety of strains, including Saccharomyces cerevisiae. S. carlsbergensis, and Candida brassicae. A temperature of 40 C has been identified as optimum for the combined cellulase and yeast systems. 

Dunne CP (1982) Relationship between extracellular proteases and the cellulase system of Trichoderma reesei. In Chibata J, Fukui J, Wingard Jr LB (eds.) Enzyme Engineering Vol 6. Plenum Press New York p 355... 

Several microorganisms have been studied with respect to the production of a cellulolytic enzyme system for the saccharification of cellu-losic materials, the most thoroughly investigated organism and best producer of cellulase being Trichoderma viride (I). Recently, good saccharification data have been reported using a strain of Penicillium (2). 

Cellulases are found in fungi and bacteria. Of commercial interest are fungal enzymes from Aspergillus or Trichoderma and a few bacterial enzymes. They are either used as a multicomponent, which contain all enzyme types and are found in Trichoderma reesei (Hypocrea jecorina), or as a monocomponent enzyme product, which consists of only one of the three types of enzymes. The multicomponent enzyme preparations can be produced from a selected cellulose overproducing strain of the wild-type organism, whereas the monocomponent cellulases are mainly produced in recombinant production systems. 

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