In
bacterial nomenclature,
Candidatus (Latin for candidate of Roman office, named after the white gown worn by Roman senators) is a component of the
taxonomic name for a bacterium that cannot be maintained in a bacteriology
culture collection. It is an interim taxonomic status for yet-to-be-cultured organisms. An example would be "
Candidatus Phytoplasma allocasuarinae". This can be abbreviated to "
Ca. Phytoplasma allocasuarinae". Candidatus status may be used when a species or genus is well characterized but yet-uncultured. With today's technology much information is obtained by
16S ribosomal RNA or even near-complete genomes with modern
metagenomics techniques.