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To obtain high expression efficiency of a mannanase gene, ThMan5A, cloned from Trichoderma harzianum MGQ2, both the full-length gene and a truncated gene ( ThMan5A△CBM) that contains only the catalytic domain, were expressed in Trichoderma reesei QM9414 using the strong constitutive promoter of the gene encoding pyruvate decarboxylase ( pdc), and purified to homogeneity, respectively. We found that truncation of the gene improved its expression efficiency as well as the enzymatic properties of the encoded protein. The recombinant strain expressing ThMan5A△CBM produced 2,460 ± 45.1 U/ml of mannanase activity in the culture supernatant; 2.3-fold higher than when expressing the full-length ThMan5A gene. In addition, the truncated mannanase had superior thermostability compared with the full-length enzyme and retained 100 % of its activity after incubation at 60 °C for 48 h. Our results clearly show that the truncated ThMan5A enzyme exhibited improved characteristics both in expression efficiency and in its thermal stability. These characteristics suggest that ThMan5A△CBM has potential applications in the food, feed, paper, and pulp industries. [ABSTRACT FROM AUTHOR]

To investigate whether enzyme production can be enhanced in the Trichoderma reesei industrial hyperproducer strain RUT C30 by manipulation of cellulase regulation, the positive regulator Xyr1 was constitutively expressed under the control of the strong T. reesei pdc promoter, resulting in significantly enhanced cellulase activity in the transformant during growth on cellulose. In addition, constitutive expression of xyr1 combined with downregulation of the negative regulator encoding gene ace1 further increased cellulase and xylanase activities. Compared with RUT C30, the resulting transformant exhibited 103, 114, and 134 % greater total secreted protein levels, filter paper activity, and CMCase activity, respectively. Surprisingly, strong increases in xyr1 basal expression levels resulted in very high levels of CMCase activity during growth on glucose. These findings demonstrate the feasibility of improving cellulase production by modifying regulator expression, and suggest an attractive new single-step approach for increasing total cellulase productivity in T. reesei. [ABSTRACT FROM AUTHOR]

The article presents information on the function of cyberinfrastructure in empowering ecological and environmental research. Cyberinfrastructure describes integrated information and communication technologies for distributed information processing and coordinated knowledge discovery, which promises to revolutionize the way that science and engineering are done in the 21st century and beyond. The National Science Foundation's TeraGrid--a key element of the U.S. and world cyberinfrastructure--has facilitated the development and operation of more than two dozen science and engineering gateways. Coupling cyberinfrastructure and geographical information system can facilitate computational thinking to analyze massive quantities of spatiotemporal data rapidly and economically.