Spindle-shaped viruses infect marine ammonia-oxidizing thaumarchaea

Ammonia-oxidizing archaea (AOA) are major players in global nitrogen cycling. The physicochemical and metabolic factors affecting the composition of AOA communities and their efficiency of resource utilization have been studied extensively. However, viral predation on AOA remains unexplored due to lack of isolated virus-host systems. Here we report on the isolation and characterization of three Nitrosopumilus spindle-shaped viruses (NSVs) that infect AOA hosts. NSVs represent a potentially important group of marine viruses with a chronic infection cycle, providing important insights into the diversity and evolution of the archaeal virosphere. The wide spread of NSVs in AOA-containing marine environments suggests that NSV predation might regulate the diversity and dynamics of AOA communities, thereby affecting the carbon and nitrogen cycling.