Syntrophosphaera thermopropionivorans gen. nov. sp. nov.

Syntrophosphaera belongs to the candidate phylum Cloacimonetes. It forms a monophyletic cluster with uncultured bacteria of the Cloacimonadaceae W5 in 16S rRNA gene phylogeny. It's closest related completely sequenced bacterium, Cloacimonas acidaminovorans, displays 86.4% 16S rRNA gene identity and 78.92% ANI. Members are proposed to be syntrophic propionate-oxidising bacteria and likely include meso- and thermophilic representatives. The genus is associated in particular with mesophilic anaerobic digestion systems. 16S rRNA gene amplicon sequencing and a novel genus-specific quantitative PCR assay showed that it outnumbered other syntrophic propionate-oxidising bacteria, such as Pelotomaculum, Smithella and Syntrophobacter, in 9 of 12 full-scale biogas reactors (Dyksma and Gallert, 2019)

The species is represented by a draft metagenome assembled genome (SMOG01000000) recovered from a propionate-degrading enrichment culture, inoculated from a thermophilic biogas reactor (PFR1)-treating biowaste.  The draft genome is 1,753,479 bp with a GC content of 36.6%, 1,463 predicted genes, an estimated completeness of 95.6% and 2.2% contamination. In enrichment culture, methane was produced from propionate, and S. thermopropionivorans was the dominant organism. The genome encodes genes for propionate oxidation via methylmalonyl-CoA and for a syntrophic, fermentative lifestyle (Dyksma and Gallert, 2019)