Identification and analysis of primary bacteria during fermentation of stinky Mandarin fish (Siniperca chuatsi)

The present work aimed to investigate the changes in physicochemical properties, volatile flavour compounds, and bacterial diversity of stinky Mandarin fish during fermentation, and identify the primary bacteria influencing the fermentation. After fermentation, the moisture, crude protein, and crude fat contents of fish decreased by 7.41, 34.15, and 5.95%, respectively. Proteobacteria was the most dominant phylum throughout fermentation, accounting for > 50% during days 1 - 2 of fermentation. At the genus level, the bacterial composition exhibited more diversity during days 1 - 2 of fermentation. However, from day 3 onward, Psychrilyobacter, Vibrio, and Psychrobacter gradually emerged as the dominant genera. Additionally, 22 key flavour compounds were identified by calculating their odour activity values. Redundancy analysis revealed that the most abundant flavour species emerged during days 6 - 7 of fermentation. Psychrilyobacter, Psychrobacter, Fusobacterium, and Morganella exhibited a positive correlation with these species.