I am looking to use a Phospholipid spike into an environmental sample (not expected to have any Fungi or other Euks), and I hope to choose a lipid with fatty acids that will cause the least interference during downstream PLFA profiling analyses.
These are mostly hydroxy fatty acids which may participiate in membrane structuring or may be any phospholipid with long chain that may bound to an amino acid.
I guess any fatty acids found in Fungi / other Eukaryots may be synthesized by Bacteria / Archaea. So maybe C17:0? (of course, it's better to check out its presence in sample first)