Spatial and temporal dynamics of microbial communities in a South African drinking water distribution system

This project investigates how microbial communities are structured and maintained across reservoirs, commercial buildings, and household taps within a full scale South African drinking water distribution system. Using dual method approaches - 16S rRNA V4 amplicon sequencing (Illumina MiSeq) and flow cytometry with PhenoFlow fingerprinting - we examined both taxonomic identity and phenotypic traits of microbial populations across 11 sites sampled biweekly for nine months (2018-2019). Our results reveal that reservoirs harbor the most variable communities, buildings maintain relatively stable microbiomes, and households exhibit intermediate variability. Environmental filtering by chlorine and infrastructure effects were stronger drivers of microbial composition than geographic distance. Integration of 16S and flow cytometry demonstrates that taxonomic divergence can coexist with functional convergence, offering new insights for monitoring and safeguarding public health in drinking water systems.