Comparative analysis of bacterial communities in traditional fermented foods

Fermented fish foods were collected from across Japan to clarify their bacterial communities during the fermentation process. Nezushi (Gero) was dominated almost exclusively by Latilactobacillus sakei, whereas nezushi (Gujo) showed greater diversity with Latilactobacillus sakei and Leuconostoc lactis. Izushi (Obihiro) closely resembled nezushi (Gero), while izushi (Sapporo) resembled nezushi (Gujo). In contrast, kabura-zushi (Kanazawa) exhibited a distinct community dominated by Leuconostoc spp. These results indicate that psychrotrophic lactic acid bacteria, primarily Latilactobacillus sakei and Leuconostoc spp., drive fermentation in izushi-style narezushi, with regional processing influencing bacterial composition. This study provides the first microbiological characterization of nezushi, revealing previously unknown features of its fermentation ecology.