Recuperação de poligalacturonases produzidas pela fermentação semisólida do resíduo agrícola do maracujá amarelo empregando sistema aquoso bifásico.

Abstract

This research was developed with the objective of to study the recovery of polygalacturonase enzymes obtained through of the solid state fermentation using as substrate the residue of passion fruit (Passiflora edulis flavicarpa) and as fermentation agent the filamentous fungus Aspergillus niger CCT 0916. The recovery was studied in two stages: initially it was determined the best conditions of the leaching process of enzymes from the fermented medium. Certain such conditions, it was studied the recovery of enzymes present in the extract obtained, using ATPS formed by PEG 10000 and potassium phosphate buffer. The study of the leaching was performed by a 23 factorial design in which the independent variables were: the solvent/mass of medium ratio (RE), contact time between the solvent and the fermented medium (TC) and intensity of agitation (AG) in the extraction procedure. In relation to ATPS, these were built with different compositions of PEG 10000, and phosphate buffer extract and characterized as to composition of the phases in equilibrium. In the study of leaching, extracts with higher polygalacturonase activity (APG) were obtained with RE of 10 mL of solvent per gram of wet substrate, TC = 45 minutes and AG = 50 rpm, which resulted in a maximum activity of 53.7 U/g, determining an appropriate condition for this stage of recovery. The parameter of major influence in this process was RE. Regarding application of the ATPS, the polygalacturonases focused on salt-rich phase, which showed 100% recovery on all systems. The best results were obtained for the ATPS with tie-line length of 42.94%, which showed purification factor of 4.17 and specific activity of 10.06 U/mg, reaching 7.48 and 18.05 U/mg respectively, i f the enzymes are activated properly. The use of ATPS in recovering polygalacturonases provided high yields and increased purity in a single step, being such an operation proper for a process of recovery and purification of enzymes.