Poster Presentation 1B-17

Wood Cellulign as an Alternative Matrix for Enzyme Immobilization

Fabrício M. Gomes¹, Grazielle S. Silva¹; Daltro G. Pinatti²;

Rosa A. Conte² and Heizir F. de Castro^1*

¹Departamento de Engenharia Química

²Departamento de Materiais

Faculdade de Engenharia Química de Lorena

Caixa Postal 116

12600-970, Lorena, SP, Brazil

E-mail: heizir@dequi.faenquil.br

Cellulignin is the product obtained from biomass acidic prehydrolysis carried out in a steel reactor lined with titanium metal. It is a catalytic fuel with an intermediate heating power between wood and coals, to be used in single or combined cycle thermoelectric power generation. Due to its high polymerization degree (35% lignin + 65% cellulose) and physical and chemical properties, such as porosity, surface area, this material can also be used as an alternative matrix for immobilizing biocatalysts. One group of industrially useful enzymes is the lipases triacylglycerol hydrolases (EC 3.1.1.3), which in organic media can reverse their mode of action such that they catalyze, with enantiomeric selectivity, ester synthesis or interesterifications.

The present work relates to a method for immobilizing microbial lipase, in this alternative matrix, attempting application in hydrolysis and ester reactions. For this purpose, lipase was immobilized on cellulignin by physical adsorption and covalent bonding (activated cellulignin with glutaraldeyde, sodium metaperiodate and carbonyldiimidazole) in the presence or absence of polyethylene glycol (PEG, MM 1500) as stabilizing agent. The activating agent and the presence of PEG-1500 in the immobilization procedure have shown a strong influence on the retention of the enzyme on the support. The values for enzyme retention varied from 20-68%, and the highest yield was obtained when the enzyme was immobilized on cellulignin activated with carbonyldiimidazole in the presence of PEG-1500. This immobilized derivative presented high hydrolytic (193.30 mmol.mg^-1.min) and synthetic activities (467.80 mmol.g^-1min) when compared with those obtained by the other tested techniques. The superiority of this immobilized system was confirmed by additional analyses such as infrared spectroscopy and elemental analysis, which demonstrated an appropriate fixation and higher protein incorporation on the support.