Kryptonia

Kryptonia is a bacterial phylum with candidate status. It is a member of the FCB group.[1]

The phylum was first proposed in 2016 following the recovery of genomes from a large-scale effort to mine metagenomic and single-cell genomic datasets for novel bacterial diversity.[2] Extensive analysis of 5.2 Tb of metagenomic data from around the world suggests members of Kryptonia are found exclusively in high-temperature pH-netural geothermal springs, such as the Jinze pool (Yunnan Province, China), Dewar Creek Spring (British Columbia, Canada), and Great Boiling Spring (Nevada, USA).[2] Due to primer mismatches, members of this phylum have been widely under-detected in 16S rRNA sequencing-based surveys of community composition.

Analysis of the first genomes recovered from this group (from four different genera) suggests that members of Kryptonia are heterotrophs with a putative capacity for iron respiration.[2] They are inferred to be incapable of some producing key metabolic compounds on their own (e.g.: biotin, certain amino acids), and thus may be metabolically dependent on other microbes in their environment, although the nature of such a relationship is unknown.[2]

The name "Kryptonia" is derived from the Greek work "krupton", which means "hidden" or "secret". This is a nod to the phylum having hitherto eluded detection due to SSU rRNA primer biases.