We used reversed phase liquid chromatography-electrospray ionization tandem mass spectrometry for direct analysis of mycolic acids (MAs) from four different cultivations of Rhodococcus erythropolis. This technique enabled us to identify and quantify the specific molecular species of MAs directly from lipid extracts of the bacterium, including the determination of their basic characteristics such as retention time and mass spectra. We identified a total of 60 molecular species of MAs by means of LC/MS. In collision-induced dissociation tandem mass spectrometry, the [M-H](-) ions eliminated two residues, i.e., meroaldehyde and carboxylate anions containing α-alkyl chains. The structural information from these fragment ions affords structural assignment of the mycolic acids, including the lengths and number of double bond(s). Two strains, i.e., R. erythropolis CCM 2595 and genetically modified strain CCM 2595 pSRK 21 phe were cultivated on two different substrates (phenol and phenol with addition of humic acids as a sole carbon source). The addition of humic acids showed that there is a marked increase of unsaturated mycolic acids, mostly in the range of 20-100 %. This effect is more pronounced in the R. erythropolis CCM 2595 strain.

• MeSH
• Biotransformation MeSH
• Chromatography, Liquid MeSH
• Phenol metabolism   MeSH
• Humic Substances MeSH
• Culture Media chemistry   MeSH
• Mycolic Acids chemistry   metabolism   MeSH
• Rhodococcus chemistry   metabolism   MeSH
• Tandem Mass Spectrometry MeSH
• Carbon metabolism   MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Phenol MeSH
• Humic Substances MeSH
• Culture Media MeSH
• Mycolic Acids MeSH
• Carbon MeSH