Trichoderma reesei enzymes

Tuerker. M. and Mavituna, E, Production of cellulase by freely suspended and immobilized cells of Trichoderma reesei, Enzyme-Microb.-Technol. 1987. vol. 9, no. 

Marquardt, R.R., Boros, D., Guenter, W. and Crow, G. (1994) The nutritive value of barley, rye, wheat and corn for young chicks as affected by use of a trichoderma reesei enzyme preparation. Animal Feed Science and Technology 45,363-378. 

Lemos, M. A., Teixeira, J. A., Domingues, M. R. M., Mota, M., and Gama, F. M., The enhancement of the cellulolytic activity of cellobiohydrolase I and endoglucanase by the addition of cellulose binding domains derived from Trichoderma reesei. Enzyme Microbial Technol 2003, 32, (1), 35—40. 

Cellulase-gold was made and applied according to (Berg et al., 1988) with sections from material embedded in Quetol 651. Chromatographically purified cellulase complex from Trichoderma reesei was obtained from Worthington Enzymes (Cat. it CEL). 

This enzyme was shown to be specific for xylan oligomers and small acetylated synthetic substrates. Many characteristics have been published recently about this type of enzyme, purified from Trichoderma reesei, and A. oryzae [6], and a different A. n/ger preparation[7]... 

Wheat straw. Wheat straw ground to 20 mesh was treated with 2% NaOH solution (wt/vol) in 1 2 (solidiliquid) ratio at 121 C for 0.5 h (i.e., 4 g NaOH/100 g wheat straw). Trichoderma reesei QMY-1 was grown on pretreated wheat straw in SSF as well as in LSF under otherwise identical culture conditions. The SSF was carried out with full nutrient concentrations in one set and with one-half nutrient concentrations in the other set to evaluate the possible deleterious effects of elevated osmotic pressure. T reesei QMY-1 produced FP cellulase of 8.6 lU/ml (430 lU/g cellulose or 172 lU/g substrate) in 22 days. This showed that the organism was able to tolerate the high salt concentrations required in the SSF. In contrast, when the nutrients were supplied in one-half concentration, FP cellulase activity dropped to 6.7 lU/ml (335 lU/g cellulose or 134 lU/g substrate). However, the maximum enzyme activity was obtained one week earlier (14 days) than that obtained with full salt concentrations (Table I). 

Teeri, T. The cellulolytic enzyme system of Trichoderma reesei Doctoral Thesis VTT Publications 38 Technical Research Center, Espoo, FL, 1987... 

The core-enzymes, prepared in our laboratory, and containing the active centers, were successfully crystallized (Dr. Jones, Uppsala, communicated) and tertiary structures will be described in the near future. Chemical modification studies on these enzymes are currently being undertaken in our laboratory identification of important catalytic residues and location of the active centers will lead to more functional information on these enzymes. Other cellulases such as some endoglucanases from Clostridium thermocel-lum (EG A, EG B, EG D) (10) and EngA and Exg from Cellulomonas fimi (19) also contain sequences of conserved, terminally located and sometimes reiterated, amino acids. Some of these sequences are preceded by proline-serine rich domains. Thus, a bistructural-bifunctional organization seems to be a rather common feature among cellulases, at least for EngA and Exg from C. fimi and the enzymes from Trichoderma reesei. 

Chromophoric substrates were also used as tools in the study of the binding of several cellulase components to their natural substrates (such as Avicel). This is illustrated here in the investigation of the synergy in binding of CBH I and CBH II from Trichoderma reesei onto Avicel. The enzymes were differentiated with CNPL (see above), which was a substrate only for CBH I (core I). Thus, the amount of CBH II adsorbed when a mixture of both enzymes was added, either simultaneously or sequentionally, to Avicel was calculated from the amount of CBH I bound (activity measurements with CNPL) subtracted from the values for total protein binding (280 nm absorbance reading). The results obtained from these experiments are summarized as follows ... 

The xylanolytic enzyme system of Trichoderma reesei, a well-known producer of cellulolytic enzymes, is versatile and well suited for the total hydrolysis of different xylans. It consists of two major, specific and several non-specific xylanases, at least one / -xylosidase, a-arabinosidase and a-glucuronidase and at least two acetyl esterases. The hydrolysis of polymeric xylans starts by the action of endoxylanases. The side-groupcleaving enzymes have their highest activities towards soluble, short xylo-oligosaccharides, and make the substituted oligosaccharides again accessible for xylanases and / -xylosidase. 

While Trichoderma reesei is best known as an efficient producer of cellulolytic enzymes, it has also been reported to produce xylanase and / -xylosidase (18-20). Two xylanases and a / -xylosidase have been purified from T. reesei (10), and two xylanases (21,22) and a / -xylosidase (5) from T. viride. We have previously shown that T. reesei produces all the enzymes needed for complete hydrolysis of native substituted xylans (23). One xylanase (24), a / -xylosidase (25), an a-arabinosidase (26), and an acetyl esterase (27) of T. reesei have so far been purified. In this chapter, the mode of action of these enzymes in the hydrolysis of different xylans is discussed. 

Table I. Xylanolytic Enzymes Isolated from Trichoderma reesei...

It has been proposed that the production of xylanases and cellulases is under separate regulatory control in some filamentous fungi (1). Hrmova et al. (42) reached a similar conclusion after monitoring the daily production of these enzymes in Trichoderma reesei QM 9414. Xylanase and cellulase activities followed independent production profiles during fungal growth. The same effect has been observed in batch cultures of T. harzianum. We have observed peak xylanase activity on the third day of growth whereas the cellulase activity peaked after day five or six (unpublished). 

Cellulolytic enzy- Trichoderma reesei AOT/isooctane Recovery of enzymes from broth [90]... 

Trichoderma reesei RUT C30 is known to be one of the best hyperpro-ducing cellulolytic fungi. Several factors, such as the amount and quality of carbon source, temperature and pH of the cultivation, and aeration, influence enzyme production of this strain. It has been indicated in previous studies that pH and the pH-controlling strategy have a great effect on the amount of cellulase produced (1-9). 

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