Gas chromatographic detection of sulphur compounds as methyl esters after growth of anaerobic bacteria in broth media

The use of a highly polar capillary column permits gas chromatographic analysis of organic acids as methyl esters. This method has found use in the study of end products of anaerobic bacteria. In addition, it also permits the detection of nonvolatile sulphur compounds which are neglected on the usual packed columns. These compounds have been identified by gas chromatography-mass spectrometry as methyl esters of 3-(methylthio)-propanoic acid and 4-(methylthio)-butanoic acid. When certain species were grown in a medium supplemented with 0·4% (w/v) DL-methionine, the relative amounts of both acids increased significantly. These nonvolatile sulphur compounds may serve as markers for specific bacteria.