The recently proposed species Eubacterium minutum and Eubacterium tardum ap
peared to be similar from their published descriptions. The aim of this stu
dy was to perform phenotypic and genetic analyses of strains of both specie
s to clarify their taxonomic position. The type strains of E. minutum and E
. tardum exhibited identical biochemical and protein profiles and their 16S
rRNA gene sequences displayed 99.9% similarity. The G+C content of the DNA
of both strains was estimated at 45 mol%. it is concluded that E. minutum
and E. tardum are synonyms; E. minutum has priority. An emended description
of E. minutum is given.