THE LABELING OF MICROORGANISMS WITH [S-35] METHIONINE, THIOATP OR INORGANIC SULFATE FOR TAXONOMIC PURPOSES

The aim of this study was to develop a rapid method of typing, widely applicable to bacteria and other microorganisms. A medium was devised in which all organisms tested would multiply. A standard method for labelling these organisms with [S-35]methionine, thioATP or inorganic sulphate was used. The labelled macromolecules present in the supernatent and the pelleted organisms separately, or the total cell lysate were treated with sodium dodecyl sulphate and dithiothreitol, and electrophoresed by one dimensional polyacrylamide gel electrophoresis. The gels were dried, and scanned in an Ambis radioscanner. In general, growth time per experiment was reduced to one tenth or less of what was previously necessary. The data from the radioscanner will be discussed in a subsequent paper. Methionine was taken up by all organisms examined and the washed pellets yielded patterns suitable for taxonomic studies. Not all organisms secreted labelled compounds but, when these were found, the patterns were simpler and equally adequate for taxonomy. The [S-35]thioATP and inorganic sulphate were not always taken up and so were of less general use. However, as less complex patterns were seen, their use may be preferred in some instances.