abstract
Laccase production from Trametes versicolor was improved in the presence of the inducers ligninosulphonates, veratryl alcohol, and xylidine respectively two-, four-, and eightfold. The thermal inactivation of the produced laccase, after partial purification with ammonium sulfate was kinetically investigated at various temperatures (60-70 A degrees C) and pH values (3.5, 4.5, and 5.5). The inactivation process followed first-order kinetics for all conditions tested, except for veratryl alcohol, for which a constant activity level was observed at the end of the inactivation, also after first-order decay. Enzyme thermostability was affected by the type of inducer used in the culture medium for the production of laccase and also by the pH of incubation mixture. Generally, laccase stability increased with pH increment, being more stable at pH 5.5, except with xylidine. At pHs 4.5 and 5.5, the three inducers significantly increased laccase thermal stability, with the higher effect being observed for pH 5.5 and ligninosulphonates, where increment of half-life times ranged from 3- to 20-fold, depending on the temperature.
keywords
BACILLUS-AMYLOLIQUEFACIENS; PLEUROTUS-OSTREATUS; ENHANCED PRODUCTION; ALPHA-AMYLASE; KRAFT PULP; INDUCTION; DELIGNIFICATION; DECOLORIZATION; PURIFICATION; EFFLUENT
subject category
Biochemistry & Molecular Biology; Biotechnology & Applied Microbiology
authors
Saraiva, JA; Tavares, APM; Xavier, AMRB
our authors
Ana Maria Rebelo Barreto Xavier
Assistant Professor
Ana Paula Mora Tavares
Assistant ResearcherGroups
G4 - Renewable Materials and Circular Economy
G5 - Biomimetic, Biological and Living Materials
acknowledgements
This work was funded by FEDER Funds through the Programa Operacional Factores de Competitividade-COMPETE and national funds through FCT-Fundacao para a Ciencia e a Tecnologia under the projects PEst-C/CTM/LA/0011/2011 and PEst-C/EQB/LA0020/2011. A.P.M. Tavares acknowledge the financial support (Programme Ciencia 2008) FCT, Portugal.