Factors Affecting the in vitro Production of Pectolytic and Cellulolytic Enzymes by Bean Leaf Pathogens Curvularia lunata and Colletotrichum dematium

Abstract

Summary Effect of p H. and temperature on in vitro production of pectolytic and cellulolytic enzymes by Curvularia lunata and Colletotrichum dematium causing leaf spot and anthracnose disease of bean were studied. The enzyme production and activity was affected by the period of incubation, initial and final p H of the medium, temperature of incubation and supplementation of glucose or pectin to the basal medium. PG1), PMG and Cx production (activity) was maximal between p H 4.0 to 5.0 at 30 to 35 °C. These enzymes were more actively secreted by C. dematium as compared to C. lunata. PME production in vitro could not be detected. Increasing amounts (0.25 to 2 %) of pectin supplementation induced increased pectolytic enzyme production by C. lunata but the production decreased in case of C. dematium. Pectin/pectate transeliminases were most active between p H. 8.0 to 8.5 at 30 °C. The pectolytic as well as cellulolytic enzymes of C. dematium origin were adversely affected by increased glucose concentration while PG and PMG production increased in C. lunata. The enzymes were found to be constitutive in C. dematium and inducible C. lunata.