RESUMO
AIMS: The aim of this work was to characterize and apply a polygalacturonase of Penicillium janthinellum new strain VI2R3M. METHODS AND RESULTS: The polygalacturonase obtained from P. janthinellum VI2R3M was incubated in cultures of passion fruit peel and was partially purified by ion-exchange chromatography and gel filtration. The enzyme showed a relative molecular mass of 102·0 kDa, maximum activity at pH 5·0, temperature of 50°C, 100% stablity at 50°C and 80% stablity at pH 3·0-5·0. The apparent Km , Vmax and Kcat values for hydrolyzing polygalacturonic acid were 2·56 mg ml-1 , 163·1 U mg-1 and 277 s-1 respectively. The polygalacturonase presented exo activity and was activated by Mg2+ . The juices treated with polygalacturonase presented increases in transmittance with reduction in colour. CONCLUSIONS: The results suggest that the new lineage P. janthinellum VI2R3M presents a high yield of an exo-polygalacturonase induced by agro-industrial residues, with excellent activity and stability in acidic pH and at 50°C. SIGNIFICANCE AND IMPACT OF THE STUDY: The use of agro-industrial residue to obtain the polygalacturonase can contribute to a decrease enzyme production cost. The results of the activity, stability to acidic pH and excellent performance in the clarification of juices show that the enzyme is promising for industrial application.
