Comparative 16S rDNA studies of Nocardia type and reference strains revealed that strain DSM 43406 T , identified as Nocardia vaccinii, was wrongly classified. The strain was aerobic, Gram-positive and produced scarce, white, branched aerial mycelium and a beige-red substrate mycelium. The reverse side of the colonies was yellow-orange. It showed chemotaxonomic markers that were consistent with its classification in the genus Nocardia. The mycolic acids had chain lengths from 50 to 58 carbon atoms. The 16S rDNA sequence showed the highest similarity to Nocardia nova (977 %) and N. vaccinii (976 %), but the strain could be clearly separated from these species and other members of the N. vaccinii cluster by significant differences in biochemical test results and unique fatty acid and mycolic acid patterns. These data led to the conclusion that the isolate represents a novel species within the genus Nocardia, for which the name Nocardia pseudovaccinii sp. nov. is proposed. The type strain is strain AR 368,38366-20Keywords : Nocardia pseudovaccinii sp. nov., polyphasic taxonomyNocardiae are distributed ubiquitously in the environment and they are common in soil (Orchard et al., 1977 ;Wang et al., 2001). They are frequently isolated from rivers (Maldonado et al., 2000) and scumming activated sludge (Lemmer & Kroppenstedt, 1984). However, despite their essentially saprophytic nature, most attention has been focused on the taxonomy of clinically significant nocardiae. Most of the validly described Nocardia species have been isolated from humans and animals, where they cause a variety of suppurative diseases, notably actinomycete mycetoma (Schaal, 1972 ;Schaal & Lee, 1992) and pulmonary infections (Gu$ rtler et al., 2001 ;Hamid et al., 2001) and nocardiosis in fish (Kudo et al., 1988 ;Isik et al., 1999) and oysters (Friedman et al., 1998), or they produce stem galls on blueberry (Demaree & Smith, 1952
