Comparative analysis of the microbiota succession and flavor formation in spontaneously fermented fish sauces made with silvery pomfret (Pampus argenteus) and little yellow croaker (Larimichthys polyactis)

Our study delved into exploring the bacterial profiles and volatile compounds during the fermentation of two distinct fish sauces, i.e., Larimichthys polyactis (LP) and Pampus argenteus (PA), and a co-occurrence network was employed to investigate the underlying relationship between flavor and microorganisms. The pH (6.97–5.66) remarkably declined while the total volatile basic nitrogen (TVB-N, 92.36–116.55 mg/100 mL) and amino acid nitrogen ( AAN, 104.49–638.68 mg/100 mL) contents gradually rose with the fermentation of LP and PA samples. Bacterial community analysis revealed that Psychrobacter was the dominant genus before LP fermentation, and its relative abundance was gradually occupied by Staphylococcus after 7M. The most dominant genus before PA fermentation was Photobacterium , while Virgibacillus emerged as the predominant genera of PA samples after 7M. Seven main volatile compounds made salient contributions (VIP ≥1.0, ROAV ≥1.0) to the flavor of LP- and PA-fermented samples, respectively. Among them, three typical genera ( Tetragenococcus , Streptococcus and Staphylococcus ) and four specific genera ( Tetragenococcus , Psychrobacter , Vagococcus and Lactobacillus ) were the core microorganisms contributing to flavor compounds in LP and PA samples, respectively. Therefore, acquiring insight into the microbes responsible for key flavors in multi-variety fermented fish sauces could provide essential indicators for optimizing commercial fermentation processes. • LP- and PA-fermented fish sauces at different stages were prepared. • 7 and 7 flavor compounds made salient contribution to the LP and PA fish sauces. • Microbial profiles exist differences among two samples and four fermentation stages. • Co-occurrence network model elucidated microbe correlations with volatile compounds. • 3 and 4 core genera were well related to key flavor compounds in LP and PA samples.