Solar radiation induces sublethal injury in Escherichia coli in seawater.

Sublethal injury was noted in Escherichia coli after cells were exposed to solar radiation. Injury was detected by differential plate counts between complete and minimal media that were observed with sunlight-exposed cells but not with cells kept in the dark. Since addition of catalase or pyruvate to minimal medium overcame or repaired this injury, the catalase system appeared to be the site of injury.