Laccase from Trametes versicolor |
| |
Authors: | Maria E A De Carvalho M C Monteiro G L Sant'Anna Jr |
| |
Institution: | (1) Departamento de Biotecnologia, Faculdade de Engenharia Química de Lorena, P.O. Box 116, CEP 12600-000 Lorena, SP, Brazil;(2) Instituto de Química, Universidade Federal do Rio de Janeiro, RJ, Brazil;(3) COPPE, Universidade Federal do Rio de Janeiro, RJ, Brazil |
| |
Abstract: | The enzyme laccase was produced by the white-rot fungus Trametes versicolor in repeated batches cultures with immobilized mycelium. Two different culture conditions were used. Enzymes produced were
evaluated regarding their stability a thigh temperatures (55°C and 65°C) and at alkaline conditions (pH 7.0 and pH 8.0) having
in view the application of these enzymes in biobleaching of hardwood Kraft pulp.
Biobleaching experiments were divided in two parts, enzymatic prebleaching followed by chemical bleaching. In the enzymatic
prebleaching the enzyme laccase was used at two conditions of pH and temperature, whereas the reaction time was fixed at 1h
in all pretreatments. In the chemical bleaching the DEDED and DEpDED sequences were used.
The enzyme action was evaluated by Kappa number, viscosity, and brightness at the end of bleaching sequences. There were obtained
values of Kappa numbers lower than control assays, viscosities compatible with industrial pulps, and brightness higher than
controls, when pulps were pretreated for 1 h with laccase at pH 8.0 and 55°C. |
| |
Keywords: | Trametes versicolor laccase biobleaching kappa number reduction brightness increase |
本文献已被 SpringerLink 等数据库收录! |
|