Lipid composition of activated sludge in a pilot plant for anaerobic ammonium oxidation

The lipid composition of the microbial community inhabiting activated sludge in a pilot reactor for the anaerobic oxidation of ammonium (anammox) at the Kur’yanovo Treatment Plant (Moscow) has been studied. The fatty acid composition is mostly based on common fatty acids C₁₄–C₁₈ (95%) with both normal and isomeric structures. The biomass of activated sludge was found to contain lipids with the so-called ladderane substances (ladder alcohols and fatty acids) that are common for anammox bacteria: C₂₀-[3]-lad-derane and C₂₀-[5]-ladderane alcohols and C₁₈- and C₂₀-[3]-ladderane and C₁₈- and C₂₀-[5]-ladderane acids. In addition, the native extract contained both simple and compound ethers of the above-mentioned substances with residues of phosphocholine, phosphoethanolamine, and phosphoglycerine. The spectra of the electron impact and tandem mass spectrometry of certain substances have been obtained and published for the first time.