Pyrazines Responsible for the Potatolike Odor Produced by Some Serratia and Cedecea Strains

Abstract

The pyrazines responsible for the potatolike odor produced by some Serratia and Cedecea cultures were identified by gas-liquid chromatography (with flame ionization and thermoionic ionization detectors) and mass spectrometry. Alkylpyrazines were produced by the six strains studied irrespective of their odors. The major alkyl-methoxypyrazine produced by Cedecea davisae was 3- sec -butyl-2-methoxypyrazine, and that produced by odoriferous Serratia strains ( S. rubidaea, S. odorifera , and S. ficaria ) was 3-isopropyl-2-methoxy-5-methyl-pyrazine. Other pyrazines produced by some strains were 3-isopropyl-2-methoxypyrazine, 3-isobutyl-2-methoxypyrazine, 3- sec -butyl-2-methoxy-5-methylpyrazine, and 3-isobutyl-2-methoxy-6-methylpyrazine. Some of these pyrazines had not previously been found as natural products or to be produced by bacteria.