Effect of kuratsuki Kocuria on sake’s taste varies depending on the combination with different sake yeast strains

Abstract

Abstract Sake brewery-inhabiting (kuratsuki) bacteria affect the flavor of sake and sake yeast mainly produces the flavor of sake. Thus, kuratsuki bacteria may alter the metabolism of sake yeast through interactions between kuratsuki bacteria and sake yeast. In this study, we used the kuratsuki Kocuria strain TGY1127_2 and three sake yeast strains, AK25, K901, and K1801. Although the Brix and acidity during sake production using AK25 differed between sake with and without kuratsuki Kocuria, those using K901 and K1801 did not differ. Thus, sake yeast AK25 interacted with kuratsuki Kocuria and changed its metabolic characteristics. Based on the Brix and acidity changes, it is uncertain whether the K901 and K1801 strains affect sake yeast metabolism. In contrast, the effect of kuratsuki Kocuria on sake’s taste varied depending on the combination of different sake yeast strains. Thus, each sake yeast strain interacted with the kuratsuki bacterium and changed its metabolic characteristics, resulting in a change in the taste of sake. The findings of this study can lead to the brewing of sake using different types of kuratsuki bacteria which can affect the sake’s taste.