Investigation of microbial diversity in limestone aquifers of the Hainich region, Thuringia, Germany

In this study we investigated the microbial diversity in the groundwater of two superimposed limestone aquifers in the Hainich region (Thuringia/Germany) by 454 pyrosequencing of bacterial 16S rRNA gene transcripts. In addition, we studied the diversity of CO2-fixing microbial communities using the Calvin-Benson-Bassham cycle by targeting the cbbM gene encoding RubisCO form II on the mRNA level. The aim of this study was to link autotrophy based on the Calvin-Benson-Bassham cycle to energy-providing metabolisms in the groundwater. Groundwater samples for this study were taken from three different sampling sites called H4-1, H5-1 (deep aquifer) and H4-3 (shallow aquifer) in November 2010 and April 2011.