Biochemical and genetic evidence for the transfer of Enterococcus solitarius Collins et al. 1989 to the genus Tetragenococcus as Tetragenococcus solitarius comb. nov.

Abstract

Phylogenetic analysis of 16S rRNA gene sequences revealed thatEnterococcus solitariusis not a member of the genusEnterococcus, but is related to species of the genusTetragenococcus. On a phylogenetic tree,E. solitariusclustered withTetragenococcus halophilusandTetragenococcus muriaticus, with which it showed the highest 16S rRNA gene sequence similarity level (about 94 %). Phenotypic studies indicated thatE. solitariuswas also unable to produce acid from lactose, providing further evidence of its affiliation to the genusTetragenococcus. DNA hybridization studies indicated thatE. solitariuswas clearly a separate species, different fromT. halophilusandT. muriaticus(reassociation levels of about 23 and 54 %, respectively). As suggested in previous studies,E. solitariusis closely related to but clearly distinct fromT. halophilus. Based upon properties that taxonomically distinguish it from species of the genusEnterococcus, it is proposed thatE. solitariusbe transferred to the genusTetragenococcusand reclassified asTetragenococcus solitariuscomb. nov. (type strain, 885/78T=ATCC 49428T=CCUG 29293T=CIP 103330T=DSM 5634T=JCM 8736T=LMG 12890T=NCTC 12193T).