Trichoderma reesei 8-glucosidase

Figure 1. Fractionation of proteins in the culture filtrate of Trichoderma reesei according to their pi values Xyl, xylanase Ara, arabinosidase AE, acetyl esterase / X, /3-xylosidase aG, a-glucuronidase / G, / -glucosidase CBH, cellobiohydrolase EG, endoglucanase. Chromatofocusing was performed in a PBE-94 anion exchange resin (Pharmacia) with a pH-gradient created by ampholyte buffers (Pharmacia). Solid line, A dotted line, pH. (Reproduced with permission from ref. 24. Copyright 1988.)...

Index Entries Cellulase production Trichoderma reesei RUT C30 pH profiling p-glucosidase shake flask fermentor. 

A commercial preparation produced by Trichoderma reesei (Spezyme CP) and supplied by Genencor (Rochester, NY, USA) was used as the cellulase enzyme in this study. This preparation was supplemented with a (3-glucosidase preparation (Novozym 188) produced by Aspergillus niger and supplied by Sigma (C6105). Various commercial xylanase preparations were kindly provided by various North American suppliers, and their cellulolytic and hemicellulolytic activities were evaluated (Table 1). BioCat xylanase was in powder form and was suspended in 100 mM sodium acetate buffer (pH 5) at a concentration of 10 mg/ml before use. 

The principal features of a mathematical model described for the enzymatic hydrolysis and fermentation of cellulose by Trichoderma reesei are the assumption of two forms of cellulose (crystalline and amorphous), two sugars (cellobiose and D-glucose), and two enzymes (cellulase and j3-D-glucosidase). An inducer-repressor-messenger RNA mechanism is used to predict enzyme formation, and pH effects are included. The model consists of 12 ordinary differential equations for 12 state variables and contains 38 parameters. The parameters were estimated from four sets of experimental data by optimization. The results appear satisfactory, and the computer programs permit simulation of a variety of system changes. 

More recently, cellulase-producing bacteria have been intensively studied. A thermally stable teta-glucosidase has been cloned from Microbispora bispora (10) that retains most of its activity even after 48 hours at 60°C, whereas the Trichoderma reesei beta-glucosidase is completely inactivated after 10 minutes at 60 C (11). Furthermore, not only is the Microbispora bispora enzyme resistant to end product inhibition, it is actually activated by a range of glucose concentrations. 

Kubicek CP (1987) Involvement of a coniditil endogluctmase tmd a plasma-membrane-bound beta-glucosidase in the induction of endoglucanase synthesis by cellulose in Trichoderma reesei. J Gen Microbiol 133 1481-1487... 

Nakazawa, H., Kawai, X, Ida, N., Shida, Y., Kobayashi, Y., Okada, FI., Xani, S., Sumitani, J., Kawaguchi, X, Morikawa, Y., and Ogasawara, W. (2011) Construction of a recombinant Trichoderma reesei strain expressing Aspergillus aculeatus fi-glucosidase 1 for efficient biomass conversion. Biotechnol Bioeng., 109, 92-99. 

Carbohydrase [(Trichoderma longibrachiatum var.) (formerly reesei)] Produced as an off white to tan, amorphous powder or as a liquid by controlled fermentation using Trichoderma longibrachiatum var. Soluble in water (the solution is usually tan to brown), but practically insoluble in alcohol, in chloroform, and in ether. Major active principles (1) cellulose, (2) /3-glucanase, (3) /3-D-glucosidase, (4) hemicellulase, and (5) pentosanase. Typical applications used in the preparation of fruit juices, wine, vegetable oils, beer, and baked goods. 

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