Assimilation and metabolism of fatty alcohols in Euglena gracilis

Abstract Euglena gracilis SM-ZK, a non-photosynthetic mutant, was grown on myristic acid or myristyl alcohol as the sole carbon source. The cells grown on myristyl alcohol accumulated a large amount of wax esters, while the cells grown on myristic acid did not. Myristyl alcohol which was taken up by the cells was directly esterified with endogenous fatty acids to form wax esters, which were then hydrolyzed and the released alcohol was oxidized. A part of the formed acid was used for the resynthesis of wax esters with newly taken up alcohol, and the remaining formic acid was converted via the μ-oxidative degradation into other cellular components and utilized for energy production. In contrast, exogenous myristic acid was catabolized directly by μ-oxidation after being taken up by the cells.