Taxonomy of the genus Paracoccus

摘要

The first representative of the current genus Paracoccus was isolated by Beijerinck and Minkman (1910) and described as ,,Micrococcus denitrificans". It was later defined by Davis et al. (1969) as Paracoccus denitrificans (with the type strain ATCC17741) because it was found to be gram-negative with a gram-negative-type cell wall and ubiquinone as an electron carrier. The generic name Paracoccus means "like a coccus" and refers to the shape of this group of bacteria. For many years P. denitrificans was the sole representative of the genus. In the available edition of "Bergey's Manual of Systematic Bacteriology" (1984-1989) the genus Paracoccus contains two species, namely P denitrificans and P. halodenitrificans (Kocur, 1984). The same information is given in "The Prokaryotes" (Van Verseveld and Stouthamer, 1992) although during the nine years that passed between the edition of the mentioned books two papers describing 3 new species of Paracoccus genus appeared. On the other hand, the validity of the taxonomic position of P. halodenitrificans was questioned already in 1990.