Das Parfüm des Todes - Ambreinbildung im menschlichen Adipocire
Zusammenfassung der Projektergebnisse
Adipocere is the product of incomplete anaerobic decomposition of human bodies and results in the in situ conservation of tissues. Only recently, the occurrence of minor proportions of ambrein in adipocere raised the question if there are possible biosynthetic pathways of its formation with the involvement of microorganisms. Ambrein is the unique constituent of ambergris, a coprolith produced by sperm whales. In this project human adipocere was studied with organic geochemical techniques and microbial community analyses to provide further clues to the origin of ambrein. It was hypothesized that ambrein formation in terrestrial and marine settings arises from similar precursor molecules and materials, and involves distinctive microorganisms and environmental conditions. A particular focus was placed on identifying precursor molecules of in situ ambrein formation and the presence of microbial lipid biomarkers and microbial communities to test the activity in the adipocere. Adipocere samples obtained from a cemetery in the Ahr valley (Rhineland Palatinate) were studied to test the hypotheses. Specific lipids were identified in the adipocere, that have not been reported in the literature as constituents before. Ambrein was mainly present in adipocere that was sampled in the pelvis, thorax and bottom location of the bodies and was assigned to originate from faecal material. However, low proportions of ambrein along with faecal steroids (coprostanol, epicoprostanol, coprostanone) were detected in the lower leg showing that migration or microbial formation of those lipids occurred in at least one individual. Squalene was present in all adipocere samples studied and might serve as possible precursor of ambrein in the adipocere. Several microbial biomarkers including glycerol monoalkylether lipids and various terminally methylated iso- and anteiso-fatty acids were detected in the adipocere. Because those lipids also occur in small proportions in human tissues it was not possible to distinguish whether they originate from bacteria, human tissue or both. The identification of 4α-methyl-5α-cholest-8(14)-en-3β-ol in the adipocere indicated the former presence and activity of microorganisms. In the upper leg and lower leg sample from one individual detectable amounts of bacterial DNA was recovered. Those DNA profiles differed significantly from the microbial communities in the surrounding soil samples. Typical bacterial phyla in the adipocere that are also part of the human intestinal microbiome were Firmicutes and Proteobacteria. The most abundant species Eubacteria corpostanoligenes with abundances of 14.2 % indicated possible cholesterol to coprostanol reduction. Our results indicated that ambrein might derive from gut contents and was preserved in the adipocere over time. The presence of distinctive anaerobic bacteria indicated their contribution to adipocere degradation and with the presence of precursor molecules possibly the formation of ambrein.
Projektbezogene Publikationen (Auswahl)
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First evidence of terrestrial ambrein formation in human adipocere. Scientific Reports, 9(1).
von der Lühe, Barbara; Mayes, Robert W.; Thiel, Volker; Dawson, Lorna A.; Graw, Matthias; Rowland, Steven J. & Fiedler, Sabine
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The perfume of death – ambrein formation in human adipocere. Poster presentation at 29th International Meeting on Organic Geochemistry. Gothenburg, Sweden.
von der Lühe, B.; Thiel, V.; Mayes, R.; Dawson, L.; Graw, M.; Rowland, S. & Fiedler, S.
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Ambrein: a minor, but common constituent of mammalian faeces?. Natural Product Research, 35(22), 4843-4848.
Rowland, Steven J.; Sutton, Paul A.; von der Lühe, Barbara; Volkman, John K.; Vane, Christopher H.; Ingram, Simon N.; Dunn, Charlotte & Claridge, Diane
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Application of steroid biomarkers in forensic pedology. Presentation at the Geobiology Unit colloquium, GFZ Potsdam, Germany.
von der Lühe, B.
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Identification and quantification of adipocere from human grave soils and its forensic application. Poster presentation at Congresso Associação Portuguesa de Ciências Forenses. Porto. Portugal.
Queirós, S.; von der Lühe B., Caldas I.M., Dawson L. & Madureira-Carvalho Á.
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Lipidic compounds found in soils surrounding human decomposing bodies and its use in forensic investigations – A narrative review. Science & Justice, 63(3), 303-312.
Queirós Sara; von der Lühe, Barbara; Silva-Bessa, Angela; Machado, Brito-da-Costa Andreia; Caldas, Inês Morais; Dawson, Lorna & Madureira-Carvalho, Áurea
