A new hydroxamate siderophore for iron supply of Salmonella

A new hydroxamate siderophore was isolated from Salmonella stanleyville strain 207/81. The organism exhibited an unusual siderophore pattern in failing to synthesize enterobactin and aerobactin. The purified siderophore was characterized by cross-feeding, paper chromatography, thin layer chromatography and paper electrophoresis. In respect to iron supply of Salmonella strains there were relationships between this and other well-known siderophores, e.g. enterobactin, aerobactin, rhodotorulic acid and ferrichrome. The new hydroxamate siderophore was detected in all Salmonella strains tested. One of the mechanisms for acquisition of iron by bacteria is the excretion of iron specific chelators, termed siderophores, the function of which is to sequester and transport iron via specific transport proteins into the cell. In Salmonella strains two types of siderophores were found. There are strains which produce enterobactin alone and some which produce enterobactin and aerobactin. In screening investigations of Salmonella, in respect to their "siderophore pattern" strains with unusual properties were detected. Beside others, the strain Salmonella stanleyville 207/81 was unable to synthesize enterobactin or aerobactin. Investigations on the effective iron supply system, presented in this paper, led to a new hydroxamate, later found in all Salmonella strains tested.