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POSTERS: Biochemistry and cell biology

Production of cell wall degrading enzymes by pathogenic Streptomyces isolated from turnip
Kerry Vermeulen - Michigan State University. Raymond Hammerschmidt- Michigan State University

Plant pathogenic Streptomyces spp grow both inter- and intracellularly. Thus it is likely that these pathogens produce cell wall and other polymer degrading enzymes as part of their process of pathogenesis. Likely candidate enzymes include pectinases and cellulases. In this study, pathogenic species of Streptomyces spp., isolated from turnip showing symptoms of scab, were screened for their ability to grow on media containing pectin, polygalacturonic acid, cellulose, or glucose as sole carbon sources, and for production of enzymes that are capable of degrading these polymers. Enzyme production was determined by plate assays and the release of reducing sugars. Isoforms of the cell wall degrading enzymes were analyzed by gel electrophoresis with substrate overlays. The production of cell wall degrading enzymes in infected tissues was also assessed. The production of enzymes was compared to virulence of the isolates on turnip tissue discs. This is the first report of cell wall and related enzyme production by Streptomyces pathogenic on turnip.