Effect of fatty acid supplementation on the lipid composition of Mycobacterium smegmatis ATCC 607, grown at 27 degrees and 37 degrees C.

Mycobacterium smegmatis ATCC 607 was grown at 27 and 37 degrees C, with and without exogenous unsaturated fatty acids, viz. elaidic, oleic and palmitoleic acids, added to the growth medium. The total lipid content of M. smegmatis ATCC 607 was lower at 27 degrees C, and with added oleic acid, when compared with the controls, but higher in presence of palmitoleic acid. At 37 degrees C no significant differences were noted in the total lipid content. In general, the total lipid content was lower with all of the fatty acid supplementations at both 27 and 37 degrees C. The phosphatidylethanolamine content was slightly higher at 27 degrees C in the presence of elaidic or palmitoleic acid, but was markedly lower with oleic acid supplementation at 37 degrees C. The cardiolipin content was lower in the presence of any of the fatty acids at 27 degrees C, and higher in the medium supplemented with elaidic or oleic acid at 37 degrees C. The unsaturated to saturated fatty acids ratio was higher with palmitoleic acid supplementation at 27 degrees C, but remained unchanged in cells grown at 37 degrees C. The modifications in mycobacterial lipids are a reflection of the organism's ability to adapt to changing growth conditions.