Trichoderma reesei

About: Trichoderma reesei is a research topic. Over the lifetime, 3832 publications have been published within this topic receiving 152877 citations. The topic is also known as: Trichoderma reesi.

Fragmentation of cellulose by the major Thermomonospora fusca cellulases, Trichoderma reesei CBHI, and their mixtures.

Abstract: binding and hydr~lysis.~~",' ~~~~ There also have been severa1 st~dies~~~~~~~,~ ~ investigating how various cellulases act synergistically to yield higher rates and extents of hydrolysis than would be predicted from the sum of the hydrolytic activities of the individual enzymes. In most of these studies only cellulase binding and reducing sugar formation were measured. Very little is known about the fragmentation activities of pure cellulases and their mixtures. It has been known for some time that cellulose undergoes fragmentation during enzymatic hydrolysis.6,28 Several investigators have observed transverse cracks and complete tranverse breakage of cellul~se.~~'~~~ ~~~~ Others have observed an increase in the number of cellulose and a shift in the volume fraction distrib~tion.~',~' The rate and extent of particle formation particles 10,18,19,23,26 * To whom all correspondence should be addressed. during hydrolysis increase linearly with increasing enzyme c~ncentration.'~,'~,~~,~'"~ Also, the rate and extent of fragmentation, as measured by changes in mean particle volume with time, decrease with decreasing initial particle size.31 It has been reported that both endoglucanases (E) and exoglucanases (CBH) are capable of fragmenting cell~lose,'~~~~~ ~~ but that the bulk of the fragmentation activity is associated with endoglucana~es.~ ~~~~ Wood et al.43 concluded that a mixture of endoglucanases and exoglucanases is necessary to fragment cotton fiber. In this study, the fragmentation activity of Thermomonospora fusca E , E , E s , Trichoderma reesei CBHI, and mixtures of these cellulases was measured. T. fusca E2 and Es were selected because of their high CMC activity, which is characteristic of highly active endoglucana~es,~' and the availability of clones for the production of these pure enzymes. T. fusca E3 was selected because it gives synergism when mixed with the other T. fusca cellulases, while i? reesei CBHI was selected to determine whether cross mixing a fungal cellulase and a bacterial cellulase would yield synergism.

Production of β-glucosidase in mixed culture of Aspergillus niger BKMF 1305 and Trichoderma reesei RUT C30

Abstract: Summary The aim of the present study was to investigate a new approach to -glucosidase production of an Aspergillus strain using cheap lignocellulosic material i.e. waste paper in order to substitute glucose, a generally used carbon source, and thereby reduce the production cost. The enzyme production was performed and optimized for the highest -glucosidase yield in cofermentation with a Trichoderma strain to support the degradation of cellulose and to provide the non-cellulolytic Aspergillus with water soluble carbon source. Batch fermentation experiments of Aspergillus niger BKMF 1305 and Trichoderma reesei RUT C30 were carried out in shake flask cultures. The factors influencing the enzyme production, such as the concentrations of nutrients and carbon source, the inoculum ratio of the two species, and the delay in A. niger inoculation were investigated using a 2 3 full factorial design. The results were analyzed with the response surface methodology using commercially available software, Statistica for Windows. All three examined factors were found significant. The highest -glucosidase activity of 3.07 IU/mL was obtained after 7 days of incubation, if 3.3 % Aspergillus and 6.7 % Trichoderma inoculum were added at the same time to modified Mandels’ medium, in which the concentration of nutrients was doubled compared to normal Mandels’ medium and the carbon source concentration was set to 20 g/L waste paper.

d-Xylose Metabolism in Hypocrea jecorina: Loss of the Xylitol Dehydrogenase Step Can Be Partially Compensated for by lad1-Encoded l-Arabinitol-4-Dehydrogenase

Abstract: With the goal of the genetic characterization of the d-xylose pathway in Hypocrea jecorina (anamorph: Trichoderma reesei), we cloned the xdh1 gene, encoding NAD-xylitol dehydrogenase, which catalyzes the second step of fungal d-xylose catabolism. This gene encodes a 363-amino-acid protein which has a mass of 38 kDa, belongs to the zinc-containing alcohol dehydrogenase family, exhibits high sequence identity to the published sequences of xylitol dehydrogenases from yeast origins, but contains a second, additional binding site for Zn2+. The enzyme catalyzed the NAD-dependent oxidation of xylitol and d-sorbitol and the NADH-dependent reduction of d-xylulose and d-fructose. No activity was observed with NADP, l-arabinose, or l-arabinitol. A single 1.4-kb transcript was formed during growth on xylan, d-xylose, l-arabinose, l-arabinitol and, at a lower abundance, xylitol, d-galactose, galactitol, and lactose but not on d-glucose and glycerol. xdh1 deletion mutants exhibited 50% reduced growth rates on d-xylose, whereas growth rates on xylitol remained unaltered. These mutants contained 30% of the xylitol dehydrogenase activity of the parent strain, indicating the presence of a second xylitol dehydrogenase. This activity was shown to be due to lad1-encoded l-arabinitol-4-dehydrogenase, because H. jecorina xdh1 lad1 double-deletion strains failed to grow on d-xylose or xylitol. In contrast, lad1 deletion strains of H. jecorina grew normally on these carbon sources. These results show that H. jecorina contains a single xylitol dehydrogenase which is encoded by xdh1 and is involved in the metabolism of d-xylose and that lad1-encoded l-arabinitol-4-dehydrogenase can compensate for it partially in mutants with a loss of xdh1 function.

Understanding the Role of the Master Regulator XYR1 in Trichoderma reesei by Global Transcriptional Analysis.

Abstract: We defined the role of the transcriptional factor–XYR1–in the filamentous fungus Trichoderma reesei during cellulosic material degradation. In this regard, we performed a global transcriptome analysis using RNA-Seq of the ∆xyr1 mutant strain of T. reesei compared with the parental strain QM9414 grown in the presence of cellulose, sophorose, and glucose as sole carbon sources. We found that 5885 genes were expressed differentially under the three tested carbon sources. Of these, 322 genes were upregulated in the presence of cellulose, while 367 and 188 were upregulated in sophorose and glucose, respectively. With respect to genes under the direct regulation of XYR1, 30 and 33 are exclusive to cellulose and sophorose, respectively. The most modulated genes in the ∆xyr1 belong to Carbohydrate-Active Enzymes (CAZymes), transcription factors, and transporters families. Moreover, we highlight the downregulation of transporters belonging to the MFS and ABC transporter families. Of these, MFS members were mostly downregulated in the presence of cellulose. In sophorose and glucose, the expression of these transporters was mainly upregulated. Our results revealed that MFS and ABC transporters could be new players in cellulose degradation and their role was shown to be carbon source-dependent. Our findings contribute to a better understanding of the regulatory mechanisms of XYR1 to control cellulase gene expression in T. reesei in the presence of cellulosic material, thereby potentially enhancing its application in several biotechnology fields.