Syntrophomonas cellicola sp. nov., a spore-forming syntrophic bacterium isolated from a distilled-spirit-fermenting cellar, and assignment of Syntrophospora bryantii to Syntrophomonas bryantii comb. nov.

A spore-forming, anaerobic, syntrophic fatty-acid-oxidizing bacterium, strain 19J-3(T), was isolated from a distilled-spirit-fermenting cellar in Hebei Province, China. The cells were slightly curved rods with a spore at the end of the cell. The optimal temperature for growth was around 37 degrees C and growth occurred in the range 25-45 degrees C. The pH range for growth was 6.5-8.5 and the optimum pH was 7.0-7.5. Crotonate was the only substrate that allowed the strain to grow in pure culture. However, the strain could oxidize saturated fatty acids with four to nine carbon atoms syntrophically in co-culture with Methanobacterium formicicum DSM 1535(T). The strain was not able to utilize sulfate, sulfite, thiosulfate, DMSO, nitrate, fumarate or Fe(III) as electron acceptor. The DNA base composition was 48.8 mol% G+C. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain 19J-3(T) was related to members of the family Syntrophomonadaceae and most closely to Syntrophospora bryantii DSM 3014(T) (94.3 % similarity) and Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (93.6 % similarity). Considering the phylogenetic relationship and phenotypic features, strain 19J-3(T) (=CGMCC 1.5041(T)=JCM 13582(T)) is designated as the type strain of a novel species of the genus Syntrophomonas, Syntrophomonas cellicola sp. nov. Based on the close phylogenetic relationship between the genera Syntrophospora and Syntrophomonas, the presence of sporulation-specific genes in the genome of Syntrophomonas wolfei subsp. wolfei DSM 2245(T) and the description of a spore-forming member of Syntrophomonas, 'Syntrophomonas erecta subsp. sporosyntropha', we propose the assignment of Syntrophospora bryantii to the genus Syntrophomonas as Syntrophomonas bryantii comb. nov.