Hyphomonas adhaerens sp. nov., Hyphomonas johnsonii sp. nov. and Hyphomonas rosenbergii sp. nov., marine budding and prosthecate bacteria.

Three strains of prosthecate, budding bacteria, MHS-2T, MHS-3T and VP6T, were isolated from marine habitats including the open ocean (the pelagic zone), the offshore region (the neritic zone) and the hydrothermal vent region. A polyphasic approach including 16S rDNA sequencing, phenotypic analyses, serology, fatty acid analyses, membrane protein profiles and DNA-DNA hybridizations was used to place these strains in the genus Hyphomonas, a taxon of the alpha-Proteobacteria. The results of these analyses also showed that strains MHS-3T, MHS-2T and VP6T each represent a new species of Hyphomonas. The names Hyphomonas adhaerens (type strain MHS-3T, ATCC 43965T), Hyphomonas johnsonii (type strain MHS-2T, ATCC 43964T) and Hyphomonas rosenbergii (type strain VP6T, ATCC 43869T) are proposed for the new species. With these additions, Hyphomonas now contains eight species.