A total of 15 strains of the genus Nocardiopsis were characterized chemotaxonomically and physiologically in an attempt to resolve their taxonomy. These strains fell into two h a , which differed in cell wall composition and menaquinone, phospholipid, and fatty acid patterns. Ten of the strains assessed in this study belong to the genus Nocardiopsis and can be assigned to five species on the basis of their physiology. Nocardiopsis dussonvillei subsp. dassonvillei is heterogeneous; N. dassonvillei remains centered on the type strain (strain DSM 43111), and the remaining strains form a new subspecies, Nocardiopsis albus subsp. albus sp. nov. (type strain, strain DSM 43377). The former N. dussonvillei subsp. prasina is recognized as a close relative of the latter organism and is designated N. dbus subsp. prasina comb. nov. Two formerly misclassified species of the genus Actinomyces not on the Approved Lists are revived as Nocardiopsis alborubidus sp. nov. and Nocardiopsis listen' sp. nov. The remaining five Nocardiopsis species (Nocardiopsis coeruleofusca, Nocardwpsis Java, Nocardiopsis longispora, Nocardiopsis mutabilis, and Nocardiopsis syringae) appear to be misclassified, and, on the basis of their similarities to the type species Saccharothrix australiensis, reclassification in the genus Saccharothrix should be considered. Nocardiopsis atra and Nocardiopsis africana were not included in this study.Lechevalier and Lechevalier showed that all members of the family Streptomycetaceae contain LL-diaminopimelic acid in their cell walls (17). Later studies of Pridham and Lyons (29) and Kroppenstedt and Kutzner (11) on the cell walls of more than 500 streptomycete species showed that some of the streptomycetes were incorrectly classified because the meso isomer and not the LL isomer of diaminopimelic acid was detected in whole-cell hydrolysates. Some of these strains lack the diagnostic sugars defined by Lechevalier and Lechevalier (17) and seem to be closely related to members of the genus Nocardiopsis. Therefore, we examined these so-called "DL streptomycetes" by using physiological and chemotaxonomic methods. For comparison we included all of the known members of the genus Nocardiopsis except Nocardiopsis antarcticus (1), for which only the fatty acids were analyzed, and "Nocardiopsis atra" (W. D. Celmer et al., U.S. patent 55194C, July 1980), which was not available to us. Nocardiopsis africana DSM 43748 was not included in our investigations because this organism has already been reclassified by Poschner et al. (25) as a member of the Actinomadura pusilla group. MATERIALS AND METHODSThe strains which we investigated and their source are listed in Table 1. Most of the Nocardiopsis species were grown at 28°C on CYC agar (Czapek-Dox agar supplemented with 2.0 g of yeast extract per liter and 6.1 g of Casamino Acids per liter) because sporulation was best on this medium. One strain, "Streptomyces listeri" DSM 40297T (T = type strain), was cultivated on Hickey-Tresner agar (8, 9). The strains that belong to the ge...

Rhodococcus sp. strain B4, isolated from a soil sample contaminated with polycyclic aromatic hydrocarbons, grows with naphthalene as the sole source of carbon and energy. Salicylate and gentisate were identified as intermediates in the catabolism of naphthalene. In contrast to the well-studied catabolic pathway encoded by the NAH7 plasmid of Pseudomonas putida, salicylate does not induce the genes of the naphthalene-degradative pathway in Rhodococcus sp. strain B4. The key enzymes of naphthalene degradation in Rhodococcus sp. strain B4 have unusual cofactor requirements. The 1,2-dihydroxynaphthalene oxygenase activity depends on NADH and the salicylate 5-hydroxylase requires NADPH, ATP, and coenzyme A.

A new plasmid, pA387, has been isolated from "Amycolatopsis sp." (DSM 43387). This plasmid could be isolated from liquid culture as well as mycelium from agar plates by a modified procedure. Plasmid pA387 is about 29.6 kb and can be cured at low frequency by protoplasting and ethidium bromide and heat treatment. Hybridization experiments showed that this plasmid is present in free form and does not integrate into the chromosome. A hybrid plasmid was constructed by cloning a 5.1-kb fragment of pA387 into the.Escherichia coli vector pDM10. This hybrid plasmid, termed pRL1, could be transformed into Amycolatopsis mediterranei and A. orientalis by electroporation. A transformation frequency of 2.2 x 103 transformants per ,ug of DNA at 12.5 kV/cm and a pulse duration of 10.8 ms was obtained in A. mediterranei, whereas 1.1 x 105 transformants per ,ug of DNA were obtained at a field strength of 7.5 kV/cm and a pulse duration of 7.6 ms in A. orientalis. Plasmid pRL1 is the first hybrid plasmid which could be used successfully for the transformation of A. mediterranei. The plasmid has a rather high copy number, is genetically stable, and can be easily reisolated from A. mediterranei. Plasmid pRL1 will be useful for further construction of a shuttle vector for E. coli and A. mediterranei and becomes the basis for the development of gene cloning techniques in Amycolatopsis spp.

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Strains ofArthrobacter catalyze a hydrolytic dehalogenation of 4-chlorobenzoate (4-CBA) to p-hydroxybenzoate. The reaction requires ATP and coenzyme A (CoA), indicating activation of the substrate via a thioester, like that reported for Pseudomonas sp. strain CBS3 (J.