Effect of ultraviolet light on pectolytic enzyme production and pathogenicity of Pseudomonas.

Ultraviolet radiation-induced mutants of the soft rot bacterium Pseudomonas marginalis were selected for loss of pathogenicity for lettuce and witloof chicory. The avirulent mutants differed from the parent pathogen in their inability to synthesize pectolytic enzymes in culture or to ferment sodium pectate or sodium polygalacturonate as the sole carbon source in media.