Pectic activities fromFusarium oxysporumf. sp.melonis: Purification and characterization of an exopolygalacturonase

Fusarium oxysporum f. sp. melonis produced an extracellular enzymic mixture with high pectic activities, (at least an exopolygalacturonase, an endopolygalacturonase and two lyases) in a medium with glucose and pectin as carbon sources. An exopolygalacturonase from this crude enzyme preparation was purified 23.8 times by Sephadex G-200 and ion-exchange HPLC. It had a Km of 6 mM, a Mr of 58 000, a pI of 6.4, optimum pH of 5 and was stable in the 3.5–6.5 pH range. This enzyme preferentially hydrolysed polygalacturonic acid, showing only 5% activity on pectin, and did not exhibit the activity of an endoenzyme.