Quantitative analysis of corynomycolic acids in fermentation broth

The mycolic acids and fatty acids of mycolic acid-containing bacteria in various types of fluids were analyzed using capillary gas chromatography and mass spectrometry. As model strains, Brevibacterium and Corynebacterium species, which have corynomycolic acids in the range of C32 C36 in the whole cell, were investigated. Optimized solvents extraction procedures for the mycolic acids and fatty acids from the culture fluids were: chloroform/methanol (1:2, v/v) as the first extraction solvents for 4 h; and chloroform/water (1:1, v/v) as the second extraction solvents for 1 h. These conditions gave above 95% recovery yields for mycolic acids from the culture fluids. The mycolic acid profile for the whole cells and the culture fluids were similar for all the media tested. Thus, the procedure described here could be applied for the identification of mycolic acid-containing bacteria in fermentation broth or liquid form of foods.