Metagenomic sequencing of low quality wastewater irrgated cabbage
5-80 ml of freshly collected water (volume depended on sample turbidity) were filtered through 0.22 m polycarbonate membranes, and filters were stored at -80C.  DNA was extracted from filters using the DNeasy PowerWater kit (catalog no. 14900-100-NF; Qiagen, USA) following the manufacturers instructions.