title: Enhancing xylanase production in the thermophilic fungus Myceliophthora thermophila by homologous overexpression of Mtxyr1.
abstract: The xylanase regulator 1 protein in Myceliophthora thermophila ATCC42464 (MtXyr1) is 60 % homologous with that of Trichoderma reesei. However, MtXyr1's regulatory role on cellulolytic and xylanolytic genes in M. thermophila is unknown. Herein, MtXyr1 was overexpressed under the control of the MtPpdc (pyruvate decarboxylase) promoter. Compared with the wild type, the extracellular xylanase activities of the transformant cultured in non-inducing and inducing media for 120 h were 25.19- and 9.04-fold higher, respectively. The Mtxyr1 mRNA level was 300-fold higher than in the wild type in corncob-containing medium. However, the filter paper activity and endoglucanase activities were unchanged in corncob-containing medium and glucose-containing medium. The different zymograms between the transformant and the wild type were analyzed and identified by mass spectrometry as three xylanases of the glycoside hydrolase (GH) family 11. Thus, overexpression of xyr1 resulted in enhanced xylanase activity in M. thermophila. Xylanase production could be improved by overexpressing Mtxyr1 in M. thermophila.
authors.affiliation: Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences, Shenzhen University, Shenzhen, 518060, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Wang
authors.forename: Yaning
authors.initials: Y
authors.lastname: Wu
authors.forename: Yanfen
authors.initials: Y
authors.lastname: Gong
authors.forename: Shaowen
authors.initials: S
authors.lastname: Yu
authors.forename: Gang
authors.initials: G
authors.lastname: Liu
mesh_terms: D004790:Enzyme Induction; D005656:Fungal Proteins / Q000096:biosynthesis* / Q000235:genetics; D015966:Gene Expression Regulation, Fungal; D011401:Promoter Regions, Genetic; D020037:Sordariales / Q000201:enzymology* / Q000235:genetics; D015534:Trans-Activators / Q000096:biosynthesis* / Q000235:genetics; D014995:Xylosidases / Q000096:biosynthesis* / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D015534:Trans-Activators; D014995:Xylosidases