info:eu-repo/semantics/article
A thermostable laccase from Thermus sp. 2.9 and its potential for delignifcation of Eucalyptus biomass
Registro en:
Navas, Laura; Martinez, Fernando; Taverna, María Eugenia; Fetherol, Morgan; Eltis, Lindsay; Nicolau, Verónica; Estenoz, Diana; Campos, Eleonora; Benintende, Graciela; Berretta, Marcelo; A thermostable laccase from Thermus sp. 2.9 and its potential for delignification of Eucalyptus biomass; AMB Express; 2 de abril del 2019.
Autor
Navas, Laura
Martinez, Fernando
Taverna, María E.
Fetherol, Morgan
Eltis, Lindsay
Nicolau, Verónica V.
Estenoz, Diana
Campos, Eleonora
Benintende, Graciela
Berreta, Marcelo
Institución
Resumen
Laccases are multicopper oxidases that are being studied for their potential application in pretreatment strategies of lignocellulosic feedstocks for bioethanol production. Here, we report the expression and characterization of a predicted laccase (LAC_2.9) from the thermophilic bacterial strain Thermus sp. 2.9 and investigate its capacity to delignify lignocellulosic biomass. The purified enzyme displayed a blue color typical of laccases, showed strict copper dependence and retained 80% of its activity after 16 h at 70 °C. At 60 °C, the enzyme oxidized 2,2′-azino-di-(3-ethylbenzthiazoline sulfonate) (ABTS) and 2,6-dimethoxyphenol (DMP) at optimal pH of 5 and 6, respectively. LAC_2.9 had higher substrate specificity (kcat/KM) for DMP with a calculated value that accounts for one of the highest reported for laccases. Further, the enzyme oxidized a phenolic lignin model dimer. The incubation of steam-exploded eucalyptus
biomass with LAC_2.9 and 1-hydroxybenzotriazole (HBT) as mediator changed the structural properties of the lignocellulose as evidenced by Fourier transform infrared (FTIR) spectroscopy and thermo-gravimetric analysis (TGA).
However, this did not increase the yield of sugars released by enzymatic saccharification. In conclusion, LAC_2.9 is a thermostable laccase with potential application in the delignification of lignocellulosic biomass. Fil: Navas, Laura(1); Martinez, Fernando (1); Taverna, María Eugenia (2,3); Fetherol, Morgan (4,5); Nicolau, Verónica (2); Estenoz, Diana (3); Campos, Eleonora (1);Berretta, Marcelo (1)
(1) Instituto de Microbiología y Zoología Agrícola, Instituto Nacional de Tecnología Agropecuaria (INTA), Nicolás Repetto y De los Reseros s/n., 1686 Hurlingham, Buenos Aires, Argentina. .
(2) UTN Regional San Francisco, Av. de la Universidad 501, (2400) San Francisco, Córdoba, Argentina;
(3) INTEC (UNL-CONICET), Güemes 3450, (3000) Santa Fe, Argentina.
(4) Department of Microbiology & Immunology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada. Eltis, Lindsay. Department of Microbiology & Immunology, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
(5) Instituto de Biotecnología, Instituto Nacional de Tecnología. Peer Reviewed