title: Back from the dead; the curious tale of the predatory cyanobacterium Vampirovibrio chlorellavorus.
abstract: An uncultured non-photosynthetic basal lineage of the Cyanobacteria, the Melainabacteria, was recently characterised by metagenomic analyses of aphotic environmental samples. However, a predatory bacterium, Vampirovibrio chlorellavorus, originally described in 1972 appears to be the first cultured representative of the Melainabacteria based on a 16S rRNA sequence recovered from a lyophilised co-culture of the organism. Here, we sequenced the genome of V. chlorellavorus directly from 36 year-old lyophilised material that could not be resuscitated confirming its identity as a member of the Melainabacteria. We identified attributes in the genome that likely allow V. chlorellavorus to function as an obligate predator of the microalga Chlorella vulgaris, and predict that it is the first described predator to use an Agrobacterium tumefaciens-like conjugative type IV secretion system to invade its host. V. chlorellavorus is the first cyanobacterium recognised to have a predatory lifestyle and further supports the assertion that Melainabacteria are non-photosynthetic.
authors.affiliation: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland , St Lucia, QLD , Australia.
authors.forename: Rochelle M
authors.initials: RM
authors.lastname: Soo
authors.affiliation: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland , St Lucia, QLD , Australia.
authors.forename: Ben J
authors.initials: BJ
authors.lastname: Woodcroft
authors.affiliation: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland , St Lucia, QLD , Australia.
authors.forename: Donovan H
authors.initials: DH
authors.lastname: Parks
authors.affiliation: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland , St Lucia, QLD , Australia ; Advanced Water Management Centre, The University of Queensland , St Lucia, QLD , Australia.
authors.forename: Gene W
authors.initials: GW
authors.lastname: Tyson
authors.affiliation: Australian Centre for Ecogenomics, School of Chemistry and Molecular Biosciences, The University of Queensland , St Lucia, QLD , Australia ; Institute for Molecular Bioscience, The University of Queensland , St Lucia, QLD , Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: Hugenholtz
keywords: Chlorella vulgaris; Cyanobacteria; Epibiotic; Melainabacteria; Obligate predator; Predatory bacteria; Vampirovibrio chlorellavorus