Classification and characteristics of Tetragenococcus halophilus derived from moromi

Abstract:

[Objective] This study aims to classify Tetragenococcus halophilus strains from soy sauce moromi mash using taxonomy analysis, and to characterize these strains. [Methods] T. halophilus strains were classified using multilocus sequence typing combined with cluster analysis of their carbohydrates metabolisms. Physiological characteristics of T. halophilus strains were studied by analyzing their tolerance to stress.[Results] Twelve T. halophilus strains of soy sauce mash origin were classified into two groups. The cluster or group type of individual strain is correlated with the environment where it derived from. T. halophilus strains C25, C33, C3 and R55 tolerated osmotic stress (high concentrations of sugar and salt), whereas strains R44, C1 and R23 exhibited better resistance to high concentrations of salt. Growth of stains C33 and R44 in acidic medium (pH 5.0) was not significantly inhibited though T. halophilus generally grows poorly under acidic conditions. Growth of T. halophilus strains was significantly inhibited when grown at low temperatures (15℃ and 25℃). [Conclusion] T. halophilus strains from soy sauce moromi mash origin were classified into two groups, using the methods based on genotype and phenotype categorizing. Strains from different groups exhibit differences in physiological characteristics.