16S rRNA gene amplicon sequencing of estuarian sediments and microcosms thereof originating from Rio Tinto, Huelva (Spain), 2022.

Rio Tinto (Huelva, Spain) is an acid rock drainage-affected fluvial estuarine system where nitrate reduction coupled to Fe(II) oxidation (NRFeOx) contributes to Fe cycling in the estuarian sediments. Microcosms of the reduced (black) layer of sediment were incubated and treated with sodium azide, lactate, nitrate and iron, or nitrate and iron and acetate. The microbial community was investigated with 16S rRNA amplicon sequencing based on DNA or RNA. Microbial 16S rRNA genes were amplified using primers 515F and 806R targeting the V4 region. Library preparation steps (Nextera, Illumina) and sequencing were performed using Illumina MiSeq sequencing system (Illumina, USA) at the Institute for Medical Microbiology and Hygiene (MGM) of the University of Tuebingen (Germany).