Sunday, April 29, 2007

Laccase production by Trametes versicolor using sugarcane bagasse residue as carbon source

Priscilla F.F. Amaral1, Mariana P. Vasquez1, Maria Alice Z. Coelho1, and Nei Pereira Jr.2. (1) Biochemical Engineering Department, Universidade Federal do Rio de Janeiro, CT, Bl. E, Cidade Universitária, 21949-900, Rio de janeiro, Brazil, (2) Biochemical Engineering Department, Federal University of Rio de Janeiro, CT, Bl. E, Cidade Universitária, 21949-900, Rio de janeiro, Brazil

There is a great interest in taking advantage of the agro-industrial wastes and exploring their use as starting materials for the production of different metabolites. Sugarcane bagasse represents the main lignocellulosic material to be considered in many tropical countries, since it is readily available in the distilleries without additional cost and has high carbohydrate and low lignin content. Sugarcane bagasse is composed of 38.1 wt% cellulose, 28.4 wt% hemicellulose, 18.4 wt% lignin and 15.1 wt% proteins and ashes. Cellulignin (CL) is the resultant solid from the acid hydrolysis of the sugarcane bagasse and its bioconversion to organic acids, xylitol and mainly ethanol produces another cellulolitic solid residue (CSR).

Lignin degradation by white rot fungi has been extensively studied, and results revealed that laccase is one of the main enzymes involved in delignification. The practical applications of laccase utilization, has lead to investigations for sources of white rot fungi enzymes. Laccases have been shown to be useful for the degradation of a variety of persistent environmental pollutants, to remove phenols from white grape must and for the pulp and paper industry in the delignification of wood fibers for pulp preparation.

The purpose of this work is to evaluate Trametes versicolor ability to degrade CL and CSR residues for laccase production. The results show that CL was the best residue for T. versicolor growth and laccase production.