Trimethylamine-Producing Bacteria on Haddock (Melanogrammus aeglefinus) Fillets during Refrigerated Storage

All of the psychrophilic groups of organisms isolated from haddock (Melanogrammus aeglefinus) fillets during storage at 3 C included organisms capable of producing trimethylamine (TMA) from trimethylamine oxide (TMAO). The percentage of TMA-producing isolates in the flora remained nearly constant during storage to spoilage, although the composition altered markedly. All Pseudomonas putrefaciens isolates were TMA producers and this organism was the most numerous TMA producer during storage. It was concluded that in this investigation P. putrefaciens was largely, if not wholely, responsible for observed TMA production. Achromobacters, although initially forming over half the TMA-producing flora, formed a decreasing percentage during storage and were not considered to contribute significantly to observed TMA production. Coryneforms were the only group to show an increase in percentage of TMA producers during storage.