TY - SER ID - arning2008lbos T1 - Lipid biomarkers of shelf sediments from upwelling regions off Namibia, Peru, and Chile AU - Arning, Esther T AU - Birgel, Daniel AU - Schulz-Vogt, Heide N AU - Holmkvist, Lars AU - Jørgensen, Bo Barker AU - Larson, Alyssa AU - Peckmann, Jörn PY - 2008 T2 - Supplement to: Arning, ET et al. (2008): Lipid Biomarker Patterns of Phosphogenic Sediments from Upwelling Regions. Geomicrobiology Journal, 25(2), 69-82, https://doi.org/10.1080/01490450801934854 PB - PANGAEA DO - 10.1594/PANGAEA.755419 UR - https://doi.org/10.1594/PANGAEA.755419 N2 - Sediments of upwelling regions off Namibia, Peru, and Chile contain dense populations of large nitrate-storing sulfide-oxidizing bacteria, Thiomargarita, Beggiatoa, and Thioploca. Increased contents of monounsaturated C16 and C18 fatty acids have been found at all stations studied, especially when a high density of sulfide oxidizers in the sediments was observed. The distribution of lipid biomarkers attributed to sulfate reducers (10MeC16:0 fatty acid, ai-C15:0 fatty acid, and mono-O-alkyl glycerol ethers) compared to the distribution of sulfide oxidizers indicate a close association between these bacteria. As a consequence, the distributions of sulfate reducers in sediments of Namibia, Peru, and Chile are closely related to differences in the motility of the various sulfide oxidizers at the three study sites. Depth profiles of mono-O-alkyl glycerol ethers have been found to correlate best with the occurrence of large sulfide-oxidizing bacteria. This suggests a particularly close link between mono-O-alkyl glycerol ether-synthesizing sulfate reducers and sulfide oxidizers. The interaction between sulfide-oxidizing bacteria and sulfate-reducing bacteria reveals intense sulfur cycling and degradation of organic matter in different sediment depths. ER -