Process Development to Recover Pectinases Produced by Solid-State

Leaching, or solid-liquid extraction, is the first step that must be done in the recovery process of a metabolite produced by Solid State Fermentation (SSF). In this work, the leaching of a Polygalacturonase (PG) produced by a strain of Aspergillus niger by SSF of citrus dried pulp was performed. A fractionated factor design 24-1 was developed to establish the influences of five factors: solid-liquid ratio, temperature, pH, agitation and surfactant addition (Tween 80). Agitation and surfactant addition effects were confounded by second order effects according to the fractionated factor design. Results showed that pH and surfactant addition did not influence the recovery process. The leaching process was characterized through the corresponding kinetic parameters for PG and total protein recovery, corresponding to first order kinetics. In the case of PG leaching, the theoretical C S was 17993 U L-1 and the k was 0.107 min-1, and in the case of total protein extraction, values were 13159 mg L -1 and 0.177 min -1 , respectively. The process was improved by using a system of six successive steps. The results showed that when a single step was performed the concentration obtained was 137 U g-1 (d.b.), while after successive extractions the PG extracted achieved a concentration of 537 U g -1 (d.b.), improving the process by 74%.