米麹からの低温発酵性Leuconostoc citreumの分離と諸性質  [in Japanese] Isolation and Characterization of Psychotrophic Leuconostoc citreum Isolated from Rice Koji  [in Japanese]

Three strains of lactic acid bacteria able to cause fermentation at a low temperature were isolated from rice koji for sake brewing. The one producing the most lactic acid at 4℃, NL7-3, was identified as Leuconostoc citreum by means of ribopatterns and the homology of 16S rDNA. This strain produced D(+)-lactic acid from citric acid as well as glucose, and showed alcohol sensitivity as well as antibacterial activity, inhibiting the growth of similar lactic acid bacteria. In sake mash brewed with viable cells of the strain instead of lactic acid, it produced lactic acid in the early period, and all bacteria cells died in the middle period. The sake thus brewed contained lactic acid, a reduced amount of citric acid, and slight amounts of malic acid in proportion to the amount of cells added. From these results, it was clear that there are L. citreum strains which, like Lactobacillus sakei and Leuconostoc mesenteroides, are capable of growing at 4℃, and which can produce bacteriocins and convert the citric acid produced by koji to D(+)-lactic acid in the seed mash of sake.