Fermentation of D-Tagatose by Human Intestinal Bacteria and Dairy Lactic Acid Bacteria

Abstract

A number of 174 normal or pathogenic human enteric bacteria and dairy lactic acid bacteria were screened for D-tagatose fermentation by incubation for 48 hours. Selection criteria for fermentation employed included a drop in pH below 5.5 and a distance to controls of more than 0.5 . Only a few of the normal occurring enteric human bacteria were able to ferment D-tagatose, among those Enterococcus faecalis , Enterococcus faecium and Lactobacillus strains . D-Tagatose fermentation seems to be common among lactic acid bacteria. Most of the analyzed dairy lactic acid bacteria fermented D-tagatose, and among those Lactobacillus , Leuconostoc and Pediococcus strains fermented most strongly, but also strains of Enterococcus , Streptococcus and Lactococcus fermented D-tagatose. None of the analyzed Bifidobacterium strains fermented tagatose. Keywords: D-tagatose, fermentation, human enteric bacteria, lactic acid bacteria, tagatose-6-phosphate pathway.