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.

Effect of pH on cellulase production of Trichoderma reesei RUT C30.

Abstract: Currently, the high market price of cellulases prohibits commercialization of the lignocellulosics-to-fuel ethanol process, which utilizes enzymes for saccharification of cellulose. For this reason research aimed at understanding and improving cellulase production is still a hot topic in cellulase research. Trichoderma reesei RUT C30 is known to be one of the best hyper producing cellulolytic fungi, which makes it an ideal test organism for research. New findings could be adopted for industrial strains in the hope of improving enzyme yields, which in turn may result in lower market price of cellulases, thus making fuel ethanol more cost competitive with fossil fuels. Being one of the factors affecting the growth and cellulase production of T. reesei, the pH of cultivation is of major interest. In the present work, numerous pH-controlling strategies were compared both in shake-flask cultures and in a fermentor. Application of various buffer systems in shake-flask experiments was also tested. Although application of buffers resulted in slightly lower cellulase activity than that obtained in non-buffered medium, β-glucosidase production was increased greatly.

Impact of light on Hypocrea jecorina and the multiple cellular roles of ENVOY in this process

Abstract: Background In fungi, light is primarily known to influence general morphogenesis and both sexual and asexual sporulation. In order to expand the knowledge on the effect of light in fungi and to determine the role of the light regulatory protein ENVOY in the implementation of this effect, we performed a global screen for genes, which are specifically effected by light in the fungus Hypocrea jecorina (anamorph Trichoderma reesei) using Rapid Subtraction Hybridization (RaSH). Based on these data, we analyzed whether these genes are influenced by ENVOY and if overexpression of ENVOY in darkness would be sufficient to execute its function.

Enzymatic hydrolysis of cellulose in aqueous two-phase systems. I. Partition of cellulases from Trichoderma reesei.

Abstract: The partitioning of endo-..beta..-glucanase, exo-..beta..-glucananse, and ..beta..-glucosidase from Trichoderma reesei QM 9414 in aqueous two-phase systems has been studied with the object of designing a phase system for continuous bioconversion of cellulose. The partitioning of the enzymes in two-phase systems composed of various water soluble polymeric compounds were studied. Systems based on dextran and polyethylene glycol (PEG) were optimal for one sidedly partitioning of the enzymes to the bottom phase. The influence of polymer molecular weights, polymer concentration, ionic composition of the medium, pH, temperature, and adsorption of the enzymes to cellulose on the enyzme partition coefficients (K) were studied. By combining the effects of polymer molecular weight and adsorption to cellulose, K values could be reduced for endo-..beta..-glucanase to 0.02 and for ..beta..-glucosidase to 0.005 at 20 degrees C in a phase system of Dvalues could be reduced for endo-..beta..-glucanase to 0.02 and for ..beta..-glucosidase to 0.005 at 20 degrees C in a phase system of Dextran 40-PEG 40000 in the presence of excess cellulose. At 50 degrees C, K values were increased by a factor of two. In a phase system based on inexpensive crude dextran and PEG, the partition coefficient for endo-..beta..-glucanase was 0.16 and for beta-glucosidasemore » was 0.14 at 20 degrees C with excess cellulose present.« less

Rce1, a novel transcriptional repressor, regulates cellulase gene expression by antagonizing the transactivator Xyr1 in Trichoderma reesei.

Abstract: Cellulase gene expression in the model cellulolytic fungus Trichoderma reesei is supposed to be controlled by an intricate regulatory network involving multiple transcription factors. Here, we identified a novel transcriptional repressor of cellulase gene expression, Rce1. Disruption of the rce1 gene not only facilitated the induced expression of cellulase genes but also led to a significant delay in terminating the induction process. However, Rce1 did not participate in Cre1-mediated catabolite repression. Electrophoretic mobility shift (EMSA) and DNase I footprinting assays in combination with chromatin immunoprecipitation (ChIP) demonstrated that Rce1 could bind directly to a cbh1 (cellobiohydrolase 1-encoding) gene promoter region containing a cluster of Xyr1 binding sites. Furthermore, competitive binding assays revealed that Rce1 antagonized Xyr1 from binding to the cbh1 promoter. These results indicate that intricate interactions exist between a variety of transcription factors to ensure tight and energy-efficient regulation of cellulase gene expression in T. reesei. This study also provides important clues regarding increased cellulase production in T. reesei.

Bioethanol production from sunflower stalk: application of chemical and biological pretreatments by response surface methodology (RSM)

Abstract: The present paper discusses response surface methodology (RSM) as an efficient tactic for predictive model and optimization of the whole experimental methods of reducing sugar and energy. In this work, the application of RSM presented for optimizing reducing sugar and energy as compared with production between chemical and biological pretreatments. All experiments applied statistical designs in order to develop a statistic multivariate analysis model that provides to consider the effect of different parameters on a process and describe the optimum values of these variables to optimize the response. Dred sunflower stalks were pretreated by sodium hydroxide (NaOH) and Trichoderma reesei as a function of two variables: concentration of NaOH (%) and T. reesei (%) and time for pretreatment (Day) to receive reducing sugar and energy. The chemical pretreatment model was characterized by 13 runs, varying the variables at two factors, NaOH (1, 1.5, 2%) and Day (1, 2, 3). The biological pretreatment model was characterized by 13 runs, varying the variables at two factors, T. reesei (1, 1.5, 2%) and Day (1, 2, 3), by central composite design experimental design. In the chemical pretreatment, experiments performed at 2% (w/v) of NaOH for 3 days were used. The chemical pretreatment model at 2% NaOH for a 3-day release reduced sugar by 5.812 g/L and energy by 92.992 kJ/L; on the other hand, biological pretreatment model at 2% T. reesei for a 3-day release reduced sugar by 3.891 g/L and energy by 62.256 kJ/L, reducing sugar starter for fermentation by 49.0670 ± 6.4660 g/L and fermentation efficiency by 71.60% at 48 h fermented time.