Dialister succinatiphilus sp. nov. and Barnesiella intestinihominis sp. nov., isolated from human faeces

Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, 186-8650 Tokyo, Japan Correspondence Masami Morotomi masami-morotomi{at}yakult.co.jp Two anaerobic, non-spore-forming, bacteria (YIT 11850 T and YIT 11860 T ) that stained Gram-negative, were isolated from human faeces. Cells of strain YIT 11850 T were coccobacilli, asaccharolytic and largely unreactive, with only traces of lactate and propionate as metabolic end products; however, strain YIT 11850 T was able to decarboxylate succinate to propionate. The DNA G+C content of strain YIT 11850 T was 51.9 mol%. Following 16S rRNA gene sequence analysis, this strain was found to be most closely related to Dialister propionicifaciens , with 95.1 % sequence similarity between the two taxa. Biochemical data supported the affiliation of strain YIT 11850 T to the genus Dialister . Strain YIT 11850 T therefore represents a novel species for which the name Dialister succinatiphilus sp. nov. is proposed; the type strain is YIT 11850 T (=DSM 21274 T =JCM 15077 T ). Cells of the other isolate, strain YIT 11860 T , were non-motile, rod-shaped, positive for aesculin hydrolysis, negative for indole production, produced succinic and acetic acids as end products of glucose metabolism and possessed a DNA G+C content of 45.5 mol%. On the basis of 16S rRNA gene sequence similarity values, this strain was shown to belong to the family ‘ Porphyromonadaceae ’ related to Barnesiella viscericola (96.0 %); similarity values with species within the family ‘ Porphyromonadaceae ’ with validly published names were less than 86 %. Biochemical data supported the affiliation of strain YIT 11860 T to the genus Barnesiella . Strain YIT 11860 T therefore represents a novel species for which the name Barnesiella intestinihominis sp. nov. is proposed; the type strain is YIT 11860 T (=DSM 21032 T =JCM 15079 T ). Abbreviations: GI, gastrointestinal The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strains YIT 11850 T and YIT 11860 T are AB370249 and AB370251 , respectively. 16S rRNA gene sequence similarity values between Dialister succinatiphilus sp. nov. and other members of the genus Dialister are available with the online version of this paper.