title: Enhancing cellulase production in Trichoderma reesei RUT C30 through combined manipulation of activating and repressing genes.
abstract: 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.
authors.affiliation: Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen 518060, China.
authors.forename: Shaowen
authors.initials: S
authors.lastname: Wang
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Jianteng
authors.initials: J
authors.lastname: Yu
authors.forename: Baiqu
authors.initials: B
authors.lastname: Huang
authors.forename: Miao
authors.initials: M
authors.lastname: Xing
mesh_terms: D002480:Cellulase / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism; D015536:Down-Regulation / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal / Q000235:genetics*; D005800:Genes, Fungal / Q000235:genetics*; D005809:Genes, Regulator / Q000235:genetics*; D005947:Glucose / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D014170:Transformation, Genetic; D014242:Trichoderma / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism*; D015854:Up-Regulation / Q000235:genetics
chemical_list: D002482:Cellulose; D002480:Cellulase; C019826:carboxymethylcellulase; D005947:Glucose