초록
The screening, biomass growth of lipase-producing fungus isolated from different sources and available at URM (University Recife Mycologia), as well as, the immobilization and utilization of the whole cells for the transesterification of babassu oil were investigated. Rhizopus oryzae (URM 3231, 4692), Mucor circinelloides (URM 4140, 4182) and Penicillium citrinum URM 4216 were considered to be good intracellular lipase producers whereas those from Mucor hiemalis URM 4144 and Mucor piriformis URM 4145 were weaker. Fungi biomass containing high lipase activities was immobilized on different biomass support particles (BSPs) and with the exception of Penicillium citrinum URM 4216 all the other fungi strains exhibited high lipase activity (20-50Ug<SUP>-1</SUP>) when immobilized in situ using polyurethane foam particles. Transesterification activities of the immobilized whole cells were evaluated in the ethanolysis reaction with babassu oil and the highest performance was attained by M. circinelloides URM 4182 giving 83.22+/-3.68% ester yield in less than 96h reaction. The biocatalyst operational stability was also assessed and an inactivation profile was found to follow the Arrhenius model, revealing values of 26 days and 2.6x10<SUP>-2</SUP>day<SUP>-1</SUP>, for half-life and a deactivation coefficient, respectively. The purified product (biodiesel) exhibited viscosity (6.63 cSt) close to the value to attend specifications by the ASTM D6751 to be used as biofuel. Results are favorable compared with data already reported in the literature and demonstrated that M. circinelloides URM 4182 whole cells is a cheaper biocatalyst that can be used in the biodiesel synthesis.