Some Properties of the Galactanase Secreted by Phytophthora infestans (Mont.) De Bary

SUMMARY: Studies on the galactanase produced by Phytophthora infestans were facilitated by an improved culture medium for enzyme production. The enzyme degraded potato pectin until a proportion of the galactose units were released; short oligosaccharides probably occurred among the products of the reaction. The enzyme rapidly reduced the viscosity of potato and lupin pectin solutions, with a slower concomitant release of reducing groups. In addition it released total carbohydrate more rapidly than galactose from potato cell walls; these results indicate that the enzyme is an endo glycano-hydrolase. It had a limited effect on the cohesion of discs of potato tuber tissue.