title: The thermophilic biomass-degrading fungus Thielavia terrestris Co3Bag1 produces a hyperthermophilic and thermostable β-1,4-xylanase with exo- and endo-activity.
abstract: A hyperthermophilic and thermostable xylanase of 82 kDa (TtXynA) was purified from the culture supernatant of T. terrestris Co3Bag1, grown on carboxymethyl cellulose (CMC), and characterized biochemically. TtXynA showed optimal xylanolytic activity at pH 5.5 and at 85 °C, and retained more than 90% of its activity at a broad pH range (4.5-10). The enzyme is highly thermostable with a half-life of 23.1 days at 65 °C, and active in the presence of several metal ions. Circular dichroism spectra strongly suggest the enzyme gains secondary structures when temperature increases. TtXynA displayed higher substrate affinity and higher catalytic efficiency towards beechwood xylan than towards birchwood xylan, oat-spelt xylan, and CMC. According to its final hydrolysis products, TtXynA displays endo-/exo-activity, yielded xylobiose, an unknown oligosaccharide containing about five residues of xylose and a small amount of xylose on beechwood xylan. Finally, this report represents the description of the first fungal hyperthermophilic xylanase which is produced by T. terrestris Co3Bag1. Since TtXynA displays relevant biochemical properties, it may be a suitable candidate for biotechnological applications carried out at high temperatures, like the enzymatic pretreatment of plant biomass for the production of bioethanol.
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: García-Huante
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México.
authors.forename: Maribel
authors.initials: M
authors.lastname: Cayetano-Cruz
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Santiago-Hernández
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México.
authors.forename: Claudia
authors.initials: C
authors.lastname: Cano-Ramírez
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México.
authors.forename: Rodolfo
authors.initials: R
authors.lastname: Marsch-Moreno
authors.affiliation: Laboratorio de Biología Molecular, UBIPRO, FES Iztacala, UNAM, Av. de los Barrios No. 1, Los Reyes Iztacala, CP 54090, Tlalnepantla, Estado de México, México.
authors.forename: Jorge E
authors.initials: JE
authors.lastname: Campos
authors.affiliation: Grupo de Fisiología de Hongos, Departamento de Alimentos y Biotecnología, Facultad de Química, UNAM. Cd. Universitaria, CP 04510, México, Ciudad de México, México.
authors.forename: Guillermo
authors.initials: G
authors.lastname: Aguilar-Osorio
authors.affiliation: Laboratorio de Investigación Bioquímica, ENMH-Instituto Politécnico Nacional, Guillermo Massieu Helguera No. 239 La Escalera Ticomán, 07320, México, Ciudad de México, México.
authors.forename: Claudia G
authors.initials: CG
authors.lastname: Benitez-Cardoza
authors.affiliation: Grupo de Microbiología Industrial, Centro de Investigación en Biotecnología Aplicada-IPN, Km 1.5 Carretera Estatal Tecuexcomac-Tepetitla, 90700, Tepetitla, Tlaxcala, México.
authors.forename: Sergio
authors.initials: S
authors.lastname: Trejo-Estrada
authors.affiliation: Departamento de Biotecnología y Bioingeniería, CINVESTAV-IPN, Av. Instituto Politécnico Nacional No. 2508, CP 07360, México, Ciudad de México, México. ehidalgo@cinvestav.mx.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Hidalgo-Lara
mesh_terms: D018533:Biomass; D002266:Carboxymethylcellulose Sodium / Q000378:metabolism*; D043364:Endo-1,4-beta Xylanases / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D006358:Hot Temperature; D007218:Industrial Microbiology; D020037:Sordariales / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D005656:Fungal Proteins; D043364:Endo-1,4-beta Xylanases; D002266:Carboxymethylcellulose Sodium
keywords: Circular dichroism; Endo-xylanase/exo-activity; Hyperthermophilic xylanase; Thermophilic fungus; Thermostable xylanase; Thielavia terrestris