Isolation of lactic acid bacteria from takanazuke as a starter strain to reduce added salt and stabilize fermentation

Abstract

Lactic acid bacteria (LAB) were isolated from takanazuke produced by using harvested takana in the Aso area. Eight strains were identified from the results of partial 16S rRNA gene sequence analysis: Enterococcus faecium, Leuconostoc mesenteroides, Lactobacillus sakei, L. curvatus, L. (para)plantarum, L. brevis, L. parabrevis, and Pediococcus parvulus. Leu. mesenteroides shared the same sequence with L. delbrueckii subsp. bulgaricus. However, they were differentiated by microscopic observation and a sugar assimilation test. In the fermentation tests using MRS and takana juice medium, L. sakei showed a different ratio of L-lactate to D-lactate from L. curvatus, although they had a similar 16S rRNA gene sequence. This difference was supposed to be based on the inhibitory effect of sodium acetate on lactate racemase. L. (para)plantarum and P. parvulus were selected as starter LABs since they decreased pH and produced high concentrations of lactate in both MRS and tanaka juice media.