Monitoring bacterial communities in ε-Polylysine-treated bighead carp (Aristichthys nobilis) fillets using culture-dependent and culture-independent techniques

The present study investigated the effect of e-Polylysine on bacterial communities, sensorial, and chemical properties [total volatile basic nitrogen (TVB-N), biogenic amines, and breakdown products of adenosine triphosphate] of bighead carp (Aristichthys nobilis) fillets stored at 4 +/- 1 degrees C. Bacterial communities were explored by the culture-dependent method and the high-throughput sequencing targeting on 16S rRNA genes. The results showed that the major genera in spoiled control samples were Aeromonas, Pseudomonas, Shewanella, and Acinetobacter. epsilon-Polylysine inhibited the growth of Pseudomonas, Shewanella, and Acinetobacter. Consequently, Aeromonas and Janthinobacterium were dominant in spoiled treated samples. The sensorial shelf-life of the control and treated groups were 8 days and 10 days, respectively. Furthermore, due to the inhibitory effect of epsilon-Polylysine on bacteria, chemical changes of the treated group were slower, reflecting as lower concentrations of TVB-N, putrescine, cadaverine, and hypoxanthine, and higher contents of inosine 5'-monophosphate and hypoxanthine riboside at the end of storage. In conclusion, epsilon-Polylysine altered the bacterial communities and delayed quality deterioration of bighead carp fillets during chilled storage.