Human enteric viruses can remain infective in surface waters for extended periods of time, posing a public health risk. Microbial activity contributes to the inactivation of waterborne enteric viruses, but while individual bacteria-virus interactions have been characterized, the importance of microbial diversity remains unknown. Here, we experimentally manipulated the diversity of bacterial communities from Lake Geneva across three seasons using a dilution-to-extinction approach and monitored the inactivation and genome decay of echovirus 11, a member of the