Ladderane lipid analysis and pore water and sediment chemistry of sediment cores from the continental shelf and slope off northwest Africa

The presence and abundance of anaerobic ammonium-oxidizing (anammox) bacteria was investigated in continental shelf and slope sediments (300-3000 m water depth) off northwest Africa in a combined approach applying quantitative polymerase chain reaction (q-PCR) analysis of anammox-specific 16S rRNA genes and anammox-specific ladderane biomarker lipids. We used the presence of an intact ladderane monoether lipid with a phosphocholine (PC) headgroup as a direct indicator for living anammox bacteria and compared it with the abundance of ladderane core lipids derived from both living and dead bacterial biomass. All investigated sediments contained ladderane lipids, both intact and core lipids, in agreement with the presence of anammoxspecific 16S rRNA gene copies, indicating that anammox occurs at all sites. […]

本研究采用结合定量聚合酶链反应（q-PCR）分析anammox特异性16S rRNA基因及anammox特异性链烷生物标志物脂质的方法，对西北非大陆架和斜坡沉积物（水深300-3000米）中厌氧氨氧化菌（anammox）的存在及丰度进行了探究。我们以存在完整的链烷单醚脂质，其具有磷胆碱（PC）头部基团，作为活体anammox细菌的直接指示物，并将其与来自活体和死体细菌生物量的链烷核心脂质丰度进行比较。所有调查的沉积物均含有链烷脂质，包括完整的和核心脂质，这与anammox特异性16S rRNA基因拷贝的存在相一致，表明anammox在所有地点均发生。