Metagenome: sediment March 25-30 cm
DNA was extracted with the DNeasy PowerSoil Pro Kit (Qiagen, Venlo, the Netherlands) following the manufacturers instructions. Upon the addition of lysis buffer, the samples were incubated at 65 C for 10 minutes and subsequently the cells were lyzed by bead beating in a tissue disruptor (Qiagen, Venlo, the Netherlands) at 50 Hz for 10 minutes. To identify the genomic potential for different nitrogen cycling processes in the studied sediment sections, the extracted DNA was sent for PCR-free metagenome sequencing (Illumina DNA PCR-free library preparation (450 bp insert), NovaSeq X platform, Macrogen, Amsterdam, the Netherlands).