A sensitive chromatographic method for the detection of pyruvyl groups in microbial polymers from sediments.

A method was developed for the quantitation of pyruvyl groups in microbial polymers using mild acid hydrolysis, o-phenylenediamine labeling, reversed-phase high-performance liquid chromatography (RP-HPLC), and fluorescence detection. The method was used to determine the pyruvate content of various microbial exopolysaccharides and to estimate the abundance of polymeric pyruvate in freshwater sediments. The results of this method were compared with those of several other pyruvate assays. The detection limit of the method was 1.6 nmol pyruvate. As little as 3.7μg of the bacterial polysaccharide xanthan gum, or from 5 to 22 mg of sediment (depending on polymeric pyruvate content), were needed for detection and quantitation of polymeric pyruvate. The results should be useful in determining the contribution of polymeric pyruvate to total metal-binding ligands in sediments.