S U M M A R YSimple chemical analyses were carried out on I 98 nocardioform bacteria by means of paper-and thin-layer chromatography. The strains considered to belong to the genus Nocardia contained the lipid LCN-A, arabinose and meso-diaminopimelic acid. All the representative strains from the 'Mycobacteriurn ' rhodochrous complex possessed this lipid though in certain cases the characteristic spot had a slightly lower RF value than that of the reference lipid LCN-A from the standard strain of Nocardia asteroides. The genera Actinomadura, Mycobacterium, Oerskovia and Streptomyces did not contain lipid LCN-A and the distribution of the other two chemical characters varied. The method used to detect lipid LCN-A is simple and reliable and permits the separation of nocardias and 'M.' rhodochrous strains from allied taxa. These results correlate well with other trends in the taxonomy of nocardioform bacteria and confirm the value of chemotaxonomic characters, especially lipids, in the classification and identification of these organisms.
SUMMARYA co-operative taxonomic study has been performed on cultures belonging to the ' rhodochrous complex '. Phenetic data on 98 cultures (78 rhodochrous cultures, 12 marker cultures with the genus designation Mycobacterium and 8 with the designation Nocardia) studied in four laboratories were collected and analysed by numerical taxonomic methods. The precipitinogenic properties and the presence of different types of mycolic acids were analysed independently to establish correlation with the numerical classification. The chemotaxonomic and serological data correlated well with the numerical analyses. The rhodochrous taxon can be distinguished from the genera Mycobacterium and Nocardia, and from the proposed genus Actinomadura; furthermore, it can be divided into at least three homogeneous subgroups. Further studies however, are needed before the question of the generic location of the rhodochrous taxon can be settled and before the taxonomic status of the rhodochrous subclusters can be resolved.
Propionibacterium propionicum belongs to the "acnes group" of propionibacteria, which is currently considered as clinically important because of its growing potential in infections, in particular with those connected with immune system dysfunctions. Propionibacteria are thought to be actinomycete-like microorganisms and may still cause diagnostic difficulties. The chloroformmethanol extracts of the cell mass of P. propionicum (type strain) gave in TLC analysis the characteristic glycolipid profile containing four major glycolipids, labeled G 1 through G 4 . These polar lipids were found to be useful chemotaxonomic markers to differentiate P. propionicum from other cutaneous propionibacteria, in particular from strains of the acnes group. Glycolipids G 1 -G 4 were isolated and purified using gel-permeation chromatography, TLC, and high performance liquid chromatography, and their structures were elucidated by compositional and methylation analyses, specific chemical degradations, MALDI-TOF mass spectrometry, and 1 H NMR and 13 C NMR spectroscopy, including HMBC, TOCSY, HMQC, and NOESY experiments. Glycolipids G 2 and G 3 possess as backbone ␣-D-Glcp-(1 3 3)-␣-D-Glcp-(1 3 1)-Gro (Gro, glycerol), in which position O-2 of the glycerol residue is acylated by a fatty acid (mainly C 15 :0) while O-3 is substituted by an alkyl ether chain. In glycolipid G 3 , an additional fatty acyl chain was linked to O-6 of the terminal glucose residue. Glycolipid G 4 was structurally related to G 2 but devoid of one glucose residue. Glycolipid G 1 was isolated in small amounts, and its structure was therefore deduced from MALDI-TOF-MS experiments alone, which revealed that it possessed the structure of G 2 but was lacking one fatty acid residue. In studies on the biological properties of P. propionicum glycolipids, the anti-P. propionicum rabbit antisera reacted in dot enzyme-immunoblotting test with G 2 and G 3 . Glycolipid G 3 was able to induce the delayed type of hypersensitivity. The results indicated that these novel ether linkage-containing polar glycolipids are immunogenic and possibly active in hypersensitivity, and thus, in pathogenesis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.