Studies on the properties of the spores of some populations of Pasteuria penetrans

Some of the properties of the spores of Pasteuria penetrans, a specific obligate parasite of plant parasitic nematodes, have been examined. These properties include size, ultrastructure, adhesion to the host, electrophoretic mobility, energy dispersive X-ray analyses of elements, ratios of d to l for the amino acids alanine and glutamic acid, and responses to chemicals and stains. The properties of three populations of P. penetrans, one from Australia (PpC) and two from the United States (PpA and PpB), were compared. The Australia population in a number of respects was different from the American populations, which did not differ from each other in these respects. PpC had larger spores, adhered more readily to its larval host, had a slightly slower electrophoretic mobility, and contained more phosphorus, sulfur, and calcium and less sodium than PpA. Furthermore, the d/l ratios for alanine and glutamic acid were higher for PpC than for PpA. In other respects those populations were similar in having the same responses to chemicals and stains and an isoelectric point close to pH 4.0.