Environmental diversity of Babelota and their interactions with protists

Most bacterial taxa are yet-to-be cultivated, thus forming the "Microbial Dark Matter" (MDM), a consortium whose ecology and biology remain largely unexplored. Candidatus Babelota is a major MDM phylum, found worldwide in various environments. Genomic evidence suggests an ancestral and unusual adaptation of all Ca. Babelota to a host dependent lifestyle with protists. However, the Ca. Babelota still remain to this day a poorly documented phylum. Thus, Ca. Babelota stands as a model for investigating MDM, which the present project proposes to study for furthering the knowledge on such elusive bacteria. To this aim, a sampling scheme was designed to cover a vast array of environments, for a period of one year.The bacterial communities were described, with a focus on Ca. Babelota presence, in associations with protists, using high throughput sequencing of 16S (Illumina) and 18S rRNA (Oxford Nanopore) amplicons.