Great Diversity of Bacterial Microbiota in Thai Local Food: “Tai-Pla”, the Salty Fermented Fish-Entrail Sauce

This study characterized the microbiota by sequencing the V3-V4 regions of prokaryotic 16S rRNA to investigate the bacterial diversity of fermented fish-entrail sauce (<i>tai-pla</i> or <i>pung-pla</i>) from five provinces in Thailand. <i>Tai-pla</i> samples made from seven different species of fish, three freshwater and four marine, were purchased. Three subsamples from each were analyzed. The samples had salt concentrations ranging from 3 to 13% and pH values ranging from 4.26 to 6.19. The top 35 genera of bacterial taxa by relative abundance were considered in more detail. Lactic acid bacteria (LAB), primarily in the order Lactobacillales (<i>Levilactobacillus</i>, <i>Companilactobacillus</i>, <i>Lactococcus</i>, <i>Latilactobacillus</i>, <i>Weissella</i>, <i>Pediococcus</i>, and <i>Ligilactobacillus</i>), were abundant in several groups of samples, as were halophilic bacteria, including <i>Halanaerobium</i>, <i>Chromohalobacter</i>, and <i>Virgibacillus</i>. Other beneficial bacterial species were frequently detected, including <i>Tetragenococcus halophilus</i> and <i>Tetragenococcus muriaticus</i>. Principal Coordinate Analysis visualization of beta diversity showed distinct bacterial community structures across <i>tai-pla</i> samples prepared with different fish species. Differences between samples may be due to the use of different raw materials, salt concentrations, recipes, processes and fermentation periods. This study provides baseline information on microbial communities and diversity in <i>tai-pla</i>, offering better insights into the production outcomes of traditional products. Further optimization of the fermentation process, such as using beneficial bacterial taxa in starter cultures, may enhance the system of food fermentation, food quality, and flavor control, supporting regulation useful for industrial applications.