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PseudonocardiaRANK: GenusTAXONOMY: Bacteria -> Terrabacteria group -> Actinobacteria -> Actinobacteria -> Pseudonocardiales -> Pseudonocardiaceae -> Pseudonocardia OVERVIEW: Aerobic, Gram-stain-positive, non-acid-fast, nonmotile, catalase-positive, actinomycetes which form branched substrate hyphae that may fragment into rod-shaped elements. Hyphae vary in thickness and in the degree of branching. Aerial hyphae, when formed, may be sterile, fragmented into chains of oval or squarish elements, or into chains of two or more spores. Substrate and aerial hyphae may exhibit cell division in different directions with a tendency to form apical or intercalary swellings. Spores are usually smooth and are produced on the substrate and/or aerial mycelium by acropetal budding and/or by basipetal septation (fragmentation), or else are formed in longitudinal pairs on vegetative hyphae and singly or in longitudinal pairs on aerial hyphae. In some species, the mycelium is covered by an electrondense outer layer. Grows on a variety of organic and synthetic media. Some species are facultative autotrophs. Cell wall contains meso-diaminopimelic acid (meso-A2pm), arabinose, and galactose. The major menaquinone is MK-8(H4) and the predominant fatty acid is iso-branched hexadecanoic acid. Mycolic acids are absent. The polar lipid profile, which varies between species, may include any of the following: phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, and glucosamine-containing phospholipids. The 16S rRNA gene sequence contains two unique regions which correspond to nucleotide positions 179–219 and 813–833 of the Streptomyces ambofaciens 16S rRNA gene (Pernodet et al., 1989). The phylogenetic position of Pseudonocardia, as determined by 16S rRNA gene sequence analysis, is in the family Pseudonocardiaceae. DNA G+C content (mol%): 68–79 (HPLC, Tm). Type species: Pseudonocardia thermophila |