title: The relation between xyr1 overexpression in Trichoderma harzianum and sugarcane bagasse saccharification performance.
abstract: This work investigates the influence of the positive regulator XYR1 of Trichoderma harzianum on the production of cellulolytic enzymes, using sugarcane bagasse as carbon source. Constitutive expression of xyr1 was achieved under the control of the strong Trichoderma reesei pki1 promoter. Five clones with xyr1 overexpression achieved higher xyr1 expression and greater enzymatic productivity when cultivated under submerged fermentation, hence validating the genetic construction for T. harzianum. Clone 5 presented a relative expression of xyr1 26-fold higher than the parent strain and exhibited 66, 37, and 36% higher values for filter paper activity, xylanase activity, and β-glucosidase activity, respectively, during cultivation in a stirred-tank bioreactor. The overexpression of xyr1 in T. harzianum resulted in an enzymatic complex with significantly improved performance in sugarcane bagasse saccharification, with an enhancement of 25% in the first 24h. Our results also show that constitutive overexpression of xyr1 leads to the induction of several important players in biomass degradation at early (24h) and also late (48h) timepoints of inoculation. However, we also observed that the carbon catabolite repressor CRE1 was upregulated in xyr1 overexpression mutants. These findings demonstrate the feasibility of improving cellulase production by modifying regulator expression and suggest an attractive approach for increasing total cellulase productivity in T. harzianum.
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil; Graduate Program of Biotechnology, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil; Molecular Biotechnology, Biochemical Technology Research Division, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1a, A-1060 Vienna, Austria. Electronic address: priscila.delabona@bioetanol.org.br.
authors.forename: Priscila
authors.initials: P
authors.lastname: da Silva Delabona
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil.
authors.forename: Gisele Nunes
authors.initials: GN
authors.lastname: Rodrigues
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil.
authors.forename: Mariane Paludetti
authors.initials: MP
authors.lastname: Zubieta
authors.affiliation: Molecular Biotechnology, Biochemical Technology Research Division, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1a, A-1060 Vienna, Austria.
authors.forename: Jonas
authors.initials: J
authors.lastname: Ramoni
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil.
authors.forename: Carla Aloia
authors.initials: CA
authors.lastname: Codima
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil.
authors.forename: Deise Juliana
authors.initials: DJ
authors.lastname: Lima
authors.affiliation: Graduate Program of Biotechnology, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil; Embrapa Instrumentação, Rua XV de Novembro 1452, São Carlos, SP, 13560-970, Brazil.
authors.forename: Cristiane Sanchez
authors.initials: CS
authors.lastname: Farinas
authors.affiliation: Brazilian Bioethanol Science and Technology Laboratory, CTBE, Pólo II de Alta Tecnologia, Rua Giuseppe Maximo Scolfaro 10000, Caixa Postal 6192, Campinas, SP, 13083-970, Brazil; Graduate Program of Biotechnology, Federal University of São Carlos, São Carlos, SP, 13565-905, Brazil.
authors.forename: José Geraldo
authors.initials: JG
authors.lastname: da Cruz Pradella
authors.affiliation: Molecular Biotechnology, Biochemical Technology Research Division, Institute of Chemical Engineering, TU Wien, Gumpendorferstrasse 1a, A-1060 Vienna, Austria.
authors.forename: Bernhard
authors.initials: B
authors.lastname: Seiboth
mesh_terms: D061249:Batch Cell Culture Techniques; D018533:Biomass; D019149:Bioreactors; D044602:Cellulases / Q000235:genetics* / Q000378:metabolism; D002482:Cellulose / Q000737:chemistry*; D005285:Fermentation; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D015533:Transcriptional Activation; D014242:Trichoderma / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D015854:Up-Regulation
chemical_list: D005656:Fungal Proteins; D014157:Transcription Factors; D002482:Cellulose; C027433:bagasse; D044602:Cellulases
keywords: Biomass saccharification; Sugarcane bagasse; Trichoderma harzianum; XYR1