THE METABOLISM OF PHYTOPATHOGENIC BACTERIA I

Abstract

A study was made of the oxidation of various substrates by intact cells and cell-free (sonic) extracts of 19 spp. of the major genera of phytopathogenic bacteria: Xanthomonas, Pseudomonas, Agro-bacterium, Erwinia and Corynebacterium. All spp. oxidized glucose, though at different rates. Gluconate was utilized by all spp. except the xanthomonads; 2-ketogluconate was used only by the 2 species of the genus Agrobacterium tested and by one sp. of the genus Erwinia (amylovora). Pyruvate, acetate, and succinate were used by all spp. except 2 of the 3 spp. of coryne-bacteria studied. CO2 was produced anaerobically from glucose and bicarbonate only by species of Erwinia. Cell-free extracts of selected species varied considerably in their activity on different phosphorylated (glucose-6-phosphate, 6-phospho-gluconate) and non-phosphorylated (gluconate, succinate, pyruvate) compounds, tested in the absence and in the presence of the cofactors adenosine triphosphate and triphosphopyridine nucleotide. The results obtained are discussed in relation to the oxidative pathways of glucose and glucose-6-phosphate metabolism.