Jaap S Sinninghe Damsté

..These moieties are under high ring strain and are synthesised by a presently unknown biosynthetic pathway...

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..This was consistent with their proposed biochemical function, namely as predominant membrane lipids of the so-called anammoxosome, the specific organelle where anammox catabolism takes place in the cell...

..The rapid rise of the rhizosolenid diatoms probably resulted from a major reorganization of the nutrient budget in the mid-Cretaceous oceans, triggered by plate tectonics...

..Our results further illustrate that microbial membrane lipid structures are far more diverse than previously recognized...

..This prevents the dense packing characteristic for the cyclopentane ring-containing GDGTs membrane lipids used by hyperthermophilic crenarchaeota to adjust their membrane fluidity to high temperatures...

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..B. Karner, E. F. DeLong, and D. M. Karl ( Nature 409:507-510, 2001) that the world's oceans contain ca. 10(28) cells of planktonic Crenarchaeota...

..Structural and stable carbon isotopic evidence suggests that these polyenes are biosynthesized by chain elongation of the C22:6n-3 fatty acid, followed by decarboxylation and introduction of double bonds at specific positions...

..5 ng/g for the ladderane fatty acids and of 0.7 ng/g for the monoether. It is foreseen that this method will allow the investigation of the occurrence of anaerobic ammonium oxidation in natural settings in much greater detail than before...

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..Our study thus suggests that heterocystous cyanobacteria played a major role in adding "new" fixed nitrogen to surface waters in past stratified oceans...

..The isolates exhibit temperature, pH, and sulfide preferences typical of their habitat. Lipids produced by these isolates matched much better with mat lipids than do lipids produced by R. castenholzii or Chloroflexus isolates...

..Moreover, this work supports the hypothesis that crenarchaeol is specific to all AOA and highlights specific lipids, which may prove useful as biomarkers for 'Ca. N. gargensis'-like AOA...

..1a AOA: they were synthesized by all three sedimentary AOA and "Candidatus Nitrosopumilus maritimus"; however, they were absent in the group I.1b AOA "Candidatus Nitrososphaera gargensis."..

..This combined application of advanced geochemical and paleogenomical tools further refined our knowledge about Holocene biogeochemical processes in Ace Lake...

..In lipid extracts from two nonsulfidic hot spring microbial mats, similar alkane-1,2-diol-based lipids were detected in minor amounts. R. castenholzii lipids are compared to lipids of mats and other thermophilic mat isolates...

..The latter core lipids have been rarely reported previously. Intact polar lipid analysis revealed that they predominantly consist of GDGTs with a phospho-glycerol headgroup...

..This study, in combination with previous studies, also suggests that hydroxylated GDGTs occur in the I.1a, but not in the I.1b, subgroup of the thaumarchaeota...

..Diester preen wax secretion was synchronized with the peak in body mass in spring, but became less well expressed under constant photoperiodic conditions and when food availability was limited...

..The assimilation of 13C-enriched cyanobacterial carbon may thus lead to enriched 13C-contents of GNSLB cell components...

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..Since the GDGT distribution in soils is much more complex, branched GDGTs in soil likely also originate from other (acido)bacteria capable of biosynthesizing these components...

..Our results suggest that TEX86 analysis by HPLC/APCI-MS is robust and can be determined with analytical errors comparable to those of other temperature proxies...

..This is consistent with the hypothesis that diester preen waxes reduce birds' smell and thereby reduce predation risk...

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