The gas chromatographic separation and mass spectrometric identification of mycolic acids ranging from Czs to CaS in Nocardia and related acid-fast groups of bacteria was established. Using this method, the molecular species of mycolic acids were clearly separated as the trimethylsilyl (TMS) derivatives of the methyl esters, according to their total carbon numbers. From the [Mlt, [M-15]+ and [M-90]t ions produced by gas chromatography mass spectrometry, the total carbon and double bond numbers were determined, while the straight and branched chain structures were identified by the mass fragment ions due to C2-C3 cleavageBased on the molecular species composition, the average carbon numbers of the mycolic acids from 16 strains of Nocardia and related taxa (Mycobacterium rhodochrous complex and Gordona bronchialis) were determined. Each species of bacteria was demonstrated to possess a characteristic profile of mycolic acid composition, and they were shown to be classified approximately into at least four groups: (1) CZs to C48 (average carbon numbers C3,-,,) mostly saturated for Nocardia erythropolis and several 'Mycobacterium rhodochrous complex'; ( 2 ) CM to Cs0 (average C43-45) monoenoic and dienoic for N. rubra, N. corallina and N. lutea; (3) C44 to CS8 (average C5,-5z) monoenoic to tetraenoic for N. asteroides and 'true' nocardiae; (4) c 5 6 to Css (average c62-a) monoenoic to pentaenoic for N. polychromogenes and Gordona bronchialis. The results indicate that the structural determination of mycolic acids by gas chromatography mass spectrometry can be one of the most useful criteria for the chemotaxonomy of Nocardia and related bacteria.

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A new acidic sphingoglycolipid has been isolated from a Gram-negative, glucose-non-fermentative (obligatory aerobic) bacterium, Flavobacterium devorans ATCC 10829, by thin-layer chromatography on silica gel after mild alkaline hydrolysis of the cellular lipids. Chemical degradation studies, thin-layer chromatographic behavior, IR and mass-spectrometric analysis of the original and reduced glycolipid with LiA1H4 revealed that the lipid contained glucuronic acid, long-chain bases, and fatty acids in a molar ratio of approximately 1:1:1. The major long-chain bases were identified by gas chromatography-mass spectrometry as dihydrosphingosine (d-18 :0) and longer homologues, while the N-acyl group was exclusively 2-hydroxy myristic acid. The most probable structure of this glycolipid appeared to be a ceramide glucuronic acid (N-acyl dihydrosphingosine 1-glucuronic acid).

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The intracellular concentrations of Na+, K+, and Cl− of an unidentified moderately halophilic bacterium were determined. When the cells were grown at a late linear growth phase in a chemically defined medium containing 1, 2, or 3 M NaCl and 5.5 mM K+, the intracellular Na+ concentration (0.90–1.15 M) was independent of the Na+ in the medium. The K+ and Cl− concentrations were roughly on the same levels, respectively (0.67–0.89 M K+; 0.70–0.98 M Cl−). The Na+ and K+ per gram protein of the whole cells were 3.85 mmol and 2.96 mmol, respectively. When the cell envelope was incubated in a 2 M NaCl solution containing 5.5 mM K+ and 0.1 mM Mg2+, the Na+ concentration in the cell envelope was very high (6.49 mmol per gram protein) and K+ was concentrated up to about 41 times of the external K+ (0.36 mmol per gram protein). The high Na+ content of the isolated cell envelope may serve as one of the keys to elucidating a role of Na+ for the maintenance of the cell rigidity in this bacterium.