Table 2 Potential cellular and metabolic sources of VOCs in three mycobacterial cultures.

From: Screening of Microbial Volatile Organic Compounds for Detection of Disease in Cattle: Development of Lab-scale Method

Mean Retention Time (min) Mycobacterial culture Compound Potential Cellular and Metabolic Associations
3.681 M. kansasii Ethanol Metabolized into acetyl CoA, used for energy in the citric acid cycle. Can be converted to acetaldehyde and then into acetic acid. Small amounts are endogenously produced via anaerobic fermentation43. Identified previously in MAP cultures48.
4.250 BCG Benzene Identified previously in M. tuberculosis cultures17, and MAP48,49.
5.309 M. kansasii
MAP
2-pentanone Identified in breath and feces of MAP infected goats50.
3-pentanone and methyl isopropyl ketone are isomer43.
9.286 BCG
MAP
Ethylbenzene Metabolite formed during degradation of styrene40. Some mycobacterial strains have been demonstrated capable of ethylbenzene degradation51,52. Identified previously in breath samples of M. tuberculosis infected humans53.
11.344 M. kansasii Styrene M. tuberculosis is capable of degrading styrene under hypoxic conditions which may play a role in intracellular survival54. Identified previously in breath samples of M. tuberculosis infected humans53.
13.354 M. kansasii Octanal A substrate for fatty aldehyde dehydrogenase and alcohol dehydrogenase43. Mycobacteria have been shown to utilize alcohol dehydrogenases in the biosynthesis of cell envelope lipids55,56.
17.788 BCG Acetophenone By-product of ethylbenzene metabolism43
Has been identified different concentrations in feces of white-tailed deer (Odocoileus virginianus) vaccinated with BCG or infected with M. bovis57.
18.769 M. kansasii Pentanedioic acid, 2,4-dimethyl, dimethyl ester; (dimethyl glutarate)  
19.048 M. kansasii 3,3-dimethyl hexane  
20.114 M. kansasii Cyclohexane, isothiocyanate Isothyocyanates are formed by enzymatic conversion of glucosinolates which are synthesized from amino acids58
  1. Potential cellular and metabolic sources of tentatively identified VOC compounds were identified for Mycobacterium bovis Bacillus Calmett- Guérin (BCG), M. avium paratuberculosis (MAP) and M. kansasii cultures.