10 research outputs found
Membrane lipids of mesophilic anaerobic bacteria thriving in peats have typical archaeal traits
The 16S ribosomal DNA based distinction between
the bacterial and archaeal domains of life is strongly
supported by the membrane lipid composition of
the two domains; Bacteria generally contain dialkyl
glycerol diester lipids, whereas Archaea produce
isoprenoid dialkyl glycerol diether and membranespanning
glycerol dialkyl glycerol tetraether (GDGT)
lipids. Here we show that a new group of ecologically
abundant membrane-spanning GDGT lipids, containing
branched instead of isoprenoid carbon skeletons,
are of a bacterial origin. This was revealed by
examining the stereochemistry of the glycerol moieties
of those branched tetraether membrane lipids,
which was found to be the bacterial 1,2-di-O-alkylsn-glycerol stereoconfiguration and not the 2,3-di-O-alkylsn-glycerol stereoconfiguration as in archaeal
membrane lipids. In addition, unequivocal evidence
for the presence of cyclopentyl moieties in these bacterial
membrane lipids was obtained by NMR. The
biochemical traits of biosynthesis of tetraether membrane
lipids and the formation of cyclopentyl moieties
through internal cyclization, which were thought to be
specific for the archaeal lineage of descent, thus also
occur in the bacterial domain of life
A mixed ladderane/n-alkyl glycerol diether in anaerobic ammonium-oxidizing bacterium
A novel glycerol diether containing ladderane and tetradecyl moieties has been identified in an anaerobic ammonium-oxidizing bacterium by GC/MS and high-field NMR spectroscopy
Membrane lipids of mesophilic anaerobic bacteria thriving in peats have typical archaeal traits
The 16S ribosomal DNA based distinction between
the bacterial and archaeal domains of life is strongly
supported by the membrane lipid composition of
the two domains; Bacteria generally contain dialkyl
glycerol diester lipids, whereas Archaea produce
isoprenoid dialkyl glycerol diether and membranespanning
glycerol dialkyl glycerol tetraether (GDGT)
lipids. Here we show that a new group of ecologically
abundant membrane-spanning GDGT lipids, containing
branched instead of isoprenoid carbon skeletons,
are of a bacterial origin. This was revealed by
examining the stereochemistry of the glycerol moieties
of those branched tetraether membrane lipids,
which was found to be the bacterial 1,2-di-O-alkylsn-glycerol stereoconfiguration and not the 2,3-di-O-alkylsn-glycerol stereoconfiguration as in archaeal
membrane lipids. In addition, unequivocal evidence
for the presence of cyclopentyl moieties in these bacterial
membrane lipids was obtained by NMR. The
biochemical traits of biosynthesis of tetraether membrane
lipids and the formation of cyclopentyl moieties
through internal cyclization, which were thought to be
specific for the archaeal lineage of descent, thus also
occur in the bacterial domain of life