Characteristics and glycerol metabolism of fumarate-reducing Enterococcus faecalis RKY1

Enterococcus faecalis RKY1, which converts fumarate to succinate with a high yield, was identified on the basis of a phylogenetic analysis of the 16S rDNA gene sequence. The strain was incubated at 38 degrees C for 18 h to examine the possible diversion of glucose or glycerol fermentation by fumarate. The products of glucose and glycerol fermentation with fumarate were quite different from those of normal fermentation, which ultimately produces lactate, in that mainly succinate is produced. Metabolic pathway stoichiometry was used to analyze the oxidation of glycerol to succinate by Enterococcus faecalis RKY1. The stoichiometric relationship between glycerol and fumarate was used as a guideline to accumulate succinate more efficiently.