Abstract:
Horizontal gene transfer (HGT), the movement of DNA between organisms, is central to microbial community function and evolution. If harnessed properly, HGT could be used to engineer microbiomes for bioremediation, selectively kill pathogens, or recover valuable resources from wastewater. However, critical knowledge gaps remain that prevent successful and reproducible precision engineering of environmental microbiomes via HGT, such as how to best deliver functional genes, how to metabolically engineer unculturable microbes, and how to identify the environmental conditions that promote the stability and function of a gene after HGT. In this talk, I describe a novel tool for high-throughput and quantitative measurements of HGT in microbial communities that uses microbial memory to record participants in gene transfer. We apply this tool to study the host range of plasmids and bacteriophages in wastewater microbial communities. We also use it to track the spread and persistence of an engineered plasmid with a dioxygenase gene introduced in a soil microbial community to enhance polycyclic aromatic hydrocarbon biodegradation.