16S rRNA gene amplicon library of AOB enrichment culture
Cells were collected by filtration onto 0.2 m polycarbonate memmbranes. DNA was isolated with Qiagen DNeasy UltraClean microbial kit. The DNA was amplified with barcoded primers targeting the V4 region of the 16SrRNA gene. The amplicon libraries were quantified, mixed and sequenced on an Illumina MiSeq.