Different seasonality of pelagic and benthic Thaumarchaeota in the North Sea

[摘要] We have examined the spatial and seasonal distribution of Thaumarchaeota inthe water column and sediment of the southern North Sea using the specificintact polar lipid (IPL) hexose-phosphohexose (HPH) crenarchaeol, as well asthaumarchaeotal 16S rRNA gene abundances and expression. In the watercolumn, a higher abundance of Thaumarchaeota was observed in the winterseason than in the summer, which is in agreement with previous studies, butthis was not the case in the sediment where Thaumarchaeota were mostabundant in spring and summer. This observation corresponds well with theidea that ammonia availability is a key factor in thaumarchaeotal nichedetermination. In the surface waters of the southern North Sea, we observeda spatial variability in HPH crenarchaeol, thaumarchaeotal 16S rRNA geneabundance and transcriptional activity that corresponded well with thedifferent water masses present. In bottom waters, a clear differentiationbased on water masses was not observed; instead, we suggest that observeddifferences in thaumarchaeotal abundance with depth may be related toresuspension from the sediment. This could be due to suspension of benthicThaumarchaeota to the water column or due to delivery of e.g. resuspendedsediment or ammonium to the water column, which could be utilized by pelagicThaumarchaeota. This study has shown that the seasonality of Thaumarchaeotain water and sediment is different and highlights the importance of watermasses, currents and sedimentary processes in determining the spatialabundance of Thaumarchaeota in the southern North Sea.

[学科分类] 地球化学与岩石