Microbial succession of grass carp (Ctenopharyngodon idellus) filets during storage at 4 °C and its contribution to biogenic amines' formation

• It was the first microbial succession study conducted on grass carp stored at 4 °C.
• Aeromonas and Pseudomonas were dominant in the spoiled grass carp.
• Analyzed the BAs production ability of strains isolated from spoiled carp filets

Investigation on the microbial succession of grass carp filets during storage at 4 °C was carried out. For identification, 16S rRNA genes of the isolated pure strains were sequenced and analyzed. Acinetobacter was dominant in fresh grass carp. Species from the genera Brevundimonas, Empedobacter, Pseudomonas, Microbacterium, Flavobacterium, Moraxella, Shewanella and Soonwooa were also detected at the initial day. The communities were dominated by Aeromonas and Acinetobacter after 6 days. Aeromonas followed by Pseudomonas was the predominant genera at the end of shelf-life of grass carp, while other genera such as Shewanella, Acinetobacter, Flavobacteriaceae and Psychrobacter were present in smaller numbers. We investigated biogenic amines' (BAs) production by six strains isolated from spoiled grass carp filets. Shewanella putrefaciens showed significantly higher abilities to produce putrescine, than those from other genera. Aeromonas veronii revealed a strong ability to produce putrescine and cadaverine. However, Pseudomonas and Acinetobacter showed little ability to produce BAs.