NMR studies of a bacterial cell culture medium (LB broth): cyclic nucleosides in yeast extracts

The composition of LB broth (tryptone, yeast extract and NaCl) was investigated by 1H, 31P‐NMR spectroscopy, FPLC and gel electrophoresis. An enexpected finding was the high level of 2′,3′‐cyclic nucleotides, detected by characteristic 31P‐NMR resonances in the region 20–21 ppm, originating from the yeast component. 31P‐NMR resonances for cyclic nucleotides were observed during the autolysis of Saccharomyces cerevisiae cells, and in model reactions of RNase with RNA.