design: Effluent sample was collected from the stage 6 of the wastewater treatment process at the Doha West Wastewater Treatment plant. Briefly, the sample was collected in sterilized glass bottles and directly stored in an ice Box of around 4 C until transportation to the laboratory. It was filtered through sterile 0.22 m Durapore hydrophilic PVDF sterile membrane (Millipore, Darmstadt, Germany). Sampling and preservation strategies were conducted according to the APHA 2008. RNA was isolated, according to the manufacturers protocol, from 25 ml of each sample using the RNeasy PowerWater Kit (Qiagen, Hilden, Germany). Library preparation was done according to the Ion 16S Metagenomics Kit protocol, templated using the IonChef System and the IonChef 320&330 chip kit (Thermo Scientific, Waltham, MA) and subsequently sequenced on the Ion S5 NGS platform as per manufacturers instruction.