Candidatus Krumholzbacterium zodletonensis gen. nov., sp nov, the first representative of the candidate phylum Krumholzbacterota phyl. nov. recovered from an anoxic sulfidic spring using genome resolved metagenomics.

The accumulation of genomes of uncultured organisms has highlighted the need for devising a taxonomic and nomenclature scheme to validate names and prevent redundancies. We here report on the recovery and analysis of four phylogenetically related genomes recovered from an anoxic sulfide and sulfur-rich spring (Zodletone spring) in southwestern Oklahoma. Phylogenetic analysis based on 120 single copy markers attested to their position as a novel distinct bacterial phylum. Genomic analysis suggests Gram-negative flagellated organisms that possess type IV pili. The organisms are predicted to be rod-shaped, slow-growers, with an anoxic, heterotrophic, and fermentative lifestyle. Predicted substrate utilization pattern includes multiple amino acids, dipeptides, tripeptides, and oligpopeptides; as well as few sugars. Predicted auxotrophies include proline, vitamin B6, lipoic acid, biotin, and vitamin B12. Assessment of the putative global distribution pattern of this novel lineage suggests its preference to anoxic marine, terrestrial, hydrocarbon-impacted, and freshwater habitats. We propose the candidatus name Krumholzbacterium zodletonensis gen. nov, sp. nov. for Zgenome0171T , with the genome serving as the type material for the novel family Krumholzbacteriaceae fam. nov., order Krumholzbacteriales ord. nov., class Krumholzbacteria class nov., and phylum Krumholzbacterota phyl. nov. The type material genome assembly is deposited in GenBank under accession number QTKG01000000.