Amino acid profile affecting the lactic acid bacterial community in <i>kimoto</i> seed mash at various brewing years

Kimoto seed mash is a traditional fermentation starter used in sake brewing that contains sufficient lactic acid produced by various lactic acid bacteria (LAB). To determine the factors influencing their community, we investigated the actively operating LAB species in addition to brewing and chemical components in the early and middle periods over different brewing years in the same sake brewery. The results showed that the composition and changes in the LAB species and amino acid profiles varied annually. Furthermore, reproduction of changes in the LAB community using a modified synthetic medium demonstrated the dependency of certain LAB strains on specific amino acids. Notably, we found that the behaviors of cocci such as Leuconostoc citreum, Lactococcus raffinolactis, Leuconostoc suionicum, and Pediococcus pentosaceus were affected by tryptophan or tyrosine requirements for each species. The metabolic activities of some LAB species were also reflected in the organic acid profile of kimoto seed mash.