Open AccessCarbon isotope‐labelling experiments indicate that ladderane lipids of anammox bacteria are synthesized by a previously undescribed, novel pathway
Author(s) -
Rattray Jayne E.,
Geenevasen Jan A.J.,
Van Niftrik Laura,
Rijpstra W. Irene C.,
Hopmans Ellen C.,
Strous Marc,
Schouten Stefan,
Jetten Mike S.M.,
Sinninghe Damsté Jaap S.
Publication year - 2009
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2008.01483.x
Subject(s) - biosynthesis , labelling , biochemistry , polyunsaturated fatty acid , cyclobutane , bacteria , fatty acid , chemistry , stereochemistry , biology , organic chemistry , ring (chemistry) , enzyme , genetics
Ladderane lipids are unusual membrane lipids of bacteria that anaerobically oxidize ammonium to dinitrogen gas (anammox). Ladderane lipids contain linearly concatenated cyclobutane rings for which the pathway of biosynthesis is currently unknown. To investigate the possible biosynthetic routes of these lipids, 2‐ 13 C‐labelled acetate was added to a culture of the anammox bacterium Candidatus Brocadia fulgida. Labelling patterns obtained by high‐field 13 C nuclear magnetic resonance spectroscopy of isolated lipids indicated that C . Brocadia fulgida synthesizes C 16:0 and iso C 16:0 fatty acids according to the known pathway of type II fatty acid biosynthesis. The 13 C‐labelling pattern of the C 8 alkyl chain of the C 20 [3] ladderane monoether also indicated the use of this route. However, carbon atoms in the cyclobutane rings and the cyclohexane ring were nonspecifically labelled and did not correspond to known patterns of fatty acid synthesis. Taken together, our results indicate that it is unlikely that ladderane lipids are formed from the cyclization of polyunsaturated fatty acids as hypothesized previously and suggest an alternative, although as yet unknown, pathway of biosynthesis.