Paracoccus marcusii sp. nov., an orange gram-negative coccus.

Phenotypic, chemotaxonomic and 16S rDNA sequence analysis of an orange Gram-negative coccus that appeared as a contaminant on a nutrient agar plate delineated a new species of the genus Paracoccus. Phenotypic features of the strain that differ from all or most of the previously described Paracoccus species include its bright orange colour, caused by the synthesis of large amounts of carotenoids (mainly astaxanthin), and its inability to use nitrate as an electron acceptor in respiration. The name Paracoccus marcusii is proposed for this organism. The type strain is DSM 11574T.