In Situ and Contact Immobilization/Adhesion of Penicillium brasilianum in Polyurethane Foam for Production of Exo-Polygalacturonase

Abstract

The present work aimed to immobilize Penicillium brasilianum fungus in situ or by contact in polyurethane foam and assess the production of exo-polygalacturonase with the immobilized fungus while evaluating the reuse, storage stability and kinetic parameters of production. The immobilization/adhesion processes in situ and in contact polyurethane resulted in activities of 2.01 ± 0.02 U/mL for both processes, results that are statistically (p < 0.05) greater than the production by free microorganism (1.70 ± 0.02 U/mL). Continuous reuse, both for contact and in situ techniques, demonstrated the possibility of reuse up to 4 times with up to 50% of the initial enzymatic activity. The evaluation of storage stability demonstrated the possibility of preserving the immobilized microorganism (in situ and by contact) for 30 days under refrigeration, without substantially affecting its productive capacity. Microbial growth rate (rx) and cell-substrate conversion factor (Y_X/S) were affected by the immobilization/adhesion process, demonstrating that the same it alters cell metabolism with regard to cell growth and substrate consumption.