Characterization and metabolism of free fatty alcohols fromEscherichia coli

Abstract
Free fatty acohols have been established as lipid components ofE. coli K‐12. Using combined gas liquid chromatography‐mass spectrometry, the major alcohols in aerobically grown cells were identified as 1‐tetradecanol (18%), 1‐hexadecanol (28%), 1‐octadecanol (14%), and 2‐pentadecanol (27%). Small amounts of 1‐hexadecenol (3%), 2‐tridecanol (8%), and 2‐tetradecanol (1.5%) were also detected. Analysis of anaerobically grown cells has shown a selective decrease of the secondary alcohols. 2‐Pentadecanol was present as only 7% of the total alcohol fraction, and only traces of 2‐tridecanol and 2‐tetradecanol were found. The major alcohols in anaerobic cells were 1‐tetradecanol, 1‐pentadecanol, 1‐hexadecenol and 1‐hexadecanol. The above observations strongly suggest two pathways for the synthesis of fatty alcohols inE. coli. One pathway synthesizes the primary alcohols and does not require molecular oxygen, and a separate pathway synthesizes the secondary alcohols and has a requirement for molecular oxygen.