AUTHOR=Bowman John P. 

TITLE=Out From the Shadows – Resolution of the Taxonomy of the Family Cryomorphaceae

JOURNAL=Frontiers in Microbiology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2020.00795

DOI=10.3389/fmicb.2020.00795

ISSN=1664-302X

ABSTRACT=<p>The family <italic>Cryomorphaceae</italic> for many years has been a poorly defined taxonomic group within the order <italic>Flavobacteriales</italic>, phylum <italic>Bacteroidetes</italic>. Members of the <italic>Cryomorphaceae</italic>, apparently consisting of multiple-family level clades, have been mostly but not exclusively detected in saline ecosystems. The problems with the taxonomy of this group have stemmed from inadequate resolution of taxonomic groups using 16S rRNA gene sequences, sparse numbers of cultivated taxa, and limited phenotypic distinctiveness. The Genome Tiaxonomc Database (GTDB), which is based on normalized taxonomic ranks includes <italic>Cryomorphaceae</italic> as containing the genera <italic>Owenweeksia</italic> and <italic>Schleiferia</italic>. This is at odds with the official taxonomy that places these genera in the family <italic>Schleiferiaceae</italic>. The other <italic>Cryomorphaceae</italic> affiliated species have even more uncertain taxonomic positions including <italic>Cryomorpha ignava</italic>. To clarify the taxonomy of <italic>Cryomorphaceae</italic>, genomes were generated for all type strains of the family <italic>Cryomorphaceae</italic> lacking such data. The GTDB-toolkit (GTDB-tk) was used to place taxa in the GTDB, which revealed novelty at the family level for some of these type strains. 16S rRNA gene sequences and concatenated protein sequences were used to further evaluate the taxonomy of the order <italic>Flavobacteriales</italic>. From the data, the GTDB enabled successful clarification of the taxonomy of the family <italic>Cryomorphaceae</italic>. A number of placeholder families were given Latinized names. It is proposed that the family <italic>Cryomorphaceae</italic> is emended to include only the species <italic>Cryomorpha ignava</italic>. The family <italic>Schleiferiaceae</italic> is emended to account for the expansion of its membership. <italic>Luteibaculum oceani</italic> represents a new family designated <italic>Luteibaculaceae</italic> fam. nov. <italic>Vicingus serpentipes</italic> is the representative of <italic>Vicingaceae</italic> fam. nov. while <italic>Salibacter halophilus</italic> represents <italic>Salibacteraceae</italic> fam. nov.</p>