Extra- and Intra-cellular -L-Arabinofuranosidase of Sclerotinia fructigena

SUMMARY: The production of both intracellular and extracellular α-l-arabinofuranosidase (AF) by Sclerotinia fructigena was demonstrated. They had different kinetic parameters, pH stability and optimal pH values. Two peaks of activity were found on gel filtration: maximum activity was associated with the peak of lower molecular weight in the culture filtrate, but with the higher molecular weight peak in the mycelial homogenate.Isoelectric-focusing studies on culture filtrates revealed two peaks of AF activity with pI 3·0 and 6·5 respectively, maximum activity being associated with the latter. In the mycelial homogenate, most of the activity was associated with a third peak of activity with pI 4·5.Physical and kinetic data suggest that the two AF activities present externally in the culture filtrates are identical with the two internal ones, with corresponding pI.