Differential induction of pectolytic enzymes of Fusarium roseum (Lk.) emend. Snyder and Hansen

Pectolytic enzymes of Fusarium roseum were differentially induced at pH 3.5 and 6.5 in solutions of specific pectic substances. Endopolygalacturonase was induced in 0.02 M mucic acid and 1% polygalacturonic acid solutions at pH 6.5 and also in a 1% pectin solution at pH 3.5. Endopolymethylgalacturonase was induced in a 1% pectin solution at pH 6.5. In addition, pectinesterase and endopectin methyl-trans-eliminase were induced in 1% pectin solutions at pH 3.5 and 6.5, respectively.Inclusion of 0.005 M CaCl2 in reaction mixtures inhibited the degradation of polygalacturonic acid by mucic and polygalacturonic acid induced polygalacturonase. In contrast, the breakdown of pectin by the pectinesterase and polygalacturonase induced in 1% pectin solutions, pH 3.5, was stimulated.