Purification and Characterization of a Polygalacturonase Produced by Wickerhamomyces anomalus

MARTOS, M.A.; BUTIUK, A.P.; N.L. ROJAS; HOURS R.A.

BRAZILIAN ARCHIVES OF BIOLOGY AND TECHNOLOGY

INST TECNOLOGIA PARANA

Año: 2014 vol. 57 p. 587 - 594

1516-8913

The aim of this work was to study the purification  and physicochemical properties of an endo-polygalacturonase (PG) produced by  Wickerhamomyces anomalusisolated from the citrus fruit peels. The enzyme was purified to homogeneity from the culture filtrate of  W. anomalusgrown on the yeast nitrogen base medium with glucose as carbon and energy source and citrus pectin as inductor. After anion-exchange chromatography and gel filtration chromatography, PG activity was eluted as a single  peak, yielding 21% of the original activity. After  dialysis and cation-exchange chromatography, only one fraction with PG activity was obtained, recovering 56% of initia enzyme activity and 1.3-fold increase in specific activity. The molecular weight of the enzyme was stimated as 43kDa by the SDS-PAGE. The enzyme exhibited maximal activity at pH 4.2 and was stable over a pH range from 3.5to 6.0 and up to 49ºC for 10 h. The Vmax  and Km values with polygalacturonic acid as substrate were 0.26 mmol/L.min and 0.173 mg/mL, respectively. Cations such as Cu+2, Fe+3, Mg+2, Mn+2and Zn+2 did not show any significant effect on PG activity but K+and Ca+2 reduced it. The purified PG was able to macerate cassava tissues.