Analysis of lactic acid bacterial flora during Miso fermentation

Abstract

This article describes a microbiological study of lactic acid bacteria involved in the fermentation process of Miso. The bacteria were counted and isolated from Miso during fermentation and, based on the results of traditional phenotypic tests, divided into nine groups. The isolates were identified by biochemical analysis and 16S rRNA sequence analysis. During Miso fermentation, the halophilic bacterium Tetragenococcus halophilus increased moderately. The non-halophilic strains displayed a complex growth pattern and were identified as Enterococcus faecium, Enterococcus durons, Enterococcus faecalis, Pediococcus acidilactici, Pediococcus pentosaceus, Lactobacillus plantarum and Weissetta confusa. The predominant species throughout the fermentation process were T. halophilus, E. faecium and E. durons. Among them, only the strains of E. faecalis and E. durons produced bacteriocins that had an antibacterial effect on B. subtilis, but had none on T. halophilus. The bacteriocin producers appear to play an important role in maintaining normal bacterial flora during Miso fermentation.