A New Actinomycete Species, Nocardiopsis lucentensis sp. nov.

A new species of the genus Nocardiopsis, for which we propose the name Nocardiopsis lucentensis sp. nov. (type strain, strain DSM 44048), was isolated from a salt marsh soil sample near Alicante, Spain. Whole-cell hydrolysates contain the meso isomer of diaminopimelic acid and no characteristic sugar; thus, the cell wall composition is type 111. Menaquinone MK-lO(H,) is the major menaquinone, and the phospholipid type is type PI11 (phosphatidylcholine present). Spore chains are rectiflexibilis, and in the early stages of sporulation zig-zag-shaped aerial hyphae are observed. This microorganism produces compatible solutes of the ectoine type and is characterized by a yellowish to yellowish brown substrate mycelium and a white aerial mycelium. This organism exhibits only 40 to 50% DNA relatedness to other Nocardiopsis spp. In 1904 Brocq-Rousseau (4) created the name Streptothrix ldassonvillei to designate a strain isolated from mildewed grain. Some years later, Liegard and Landrieu (33) isolated a microorganism from a case of conjunctivitis which they considered to be identical to Streptothrix dassonvillei but which they assigned to the genus Nocardia. Gordon and Horan (18) discovered that the macroscopic appearance and a number of the physiological characteristics of Nocardia dassonvillei were similar to those of Streptomyces griseus. Subsequently, Lechevalier and Lechevalier (30) described the genus Actinomadura to harbor Nocardia madurae (Vincent) Blanchard (the type species), Nocardia pelletieri (Laveran) Pinoy, and Nocardia dassonvillei (Brocq-Rousseau) Liegard and Landrieu. However, striking morphological differences of Actinomadura dassonvillei (e.g., the mode of sporulation of the aerial mycelium, the nature of the substrate mycelium, and the lack of madurose in whole-cell hydrolysates) led Meyer to transfer this species to a new genus, Nocardiopsis, as Nocardiopsis dassonvillei (35). The genus Nocardiopsis was described to comprise strains that exhibit fragmenting substrate and aerial mycelia and have cell wall chemotype I11 (meso isomer of diaminopimelic acid and no characteristic sugar in whole-cell hydrolysates). An earlier description of the genus included microorganisms with a type PI11 phospholipid pattern sensu Lechevalier et al. (32) (phosphatidylcholine as a diagnostic phospholipid), as well as microorganisms with a type PIV phospholipid pattern (glucosamine-containing phospholipid). In recent studies (20, 21, 24, 28), strains which possess type PIV phospholipids, including Nocardiopsis coeruleofusca (41, 42), Nocardiopsis flava (13,41,42), Nocardiopsis longispora (41, 421, Nocardiopsis mutabilis (43), Nocardiopsis mutabilis subsp. cryophilus (49, and Nocardiopsis yringae (14), were found to contain rhamnose and large amounts of galactose in whole-cell hydrolysates (the sugar pattern characteristic of the genus Saccharothrix [29]) and therefore were reclassified in the genus Saccharothrix. Another species, Nocardiupsis afncana, was found to belong to the genus Microtetraspora (25). Phenetic data indicated that the single remaining species in the genus, Nocardiopsis antarctica (l), is identical to the type strain of Nocardiopsis dassonvillei (36). To maintain the integrity of the genus Nocardiopsis, only those actinomycete isolates should be