Solar radiation is shown to select for pigmented bacteria National Health and Environmental Effects Research Laboratory Western Ecology Division 200 SW 35th Street Corvallis, Oregon 97333 Tong, Yongyi, and Bruce Lighthart.
Solar radiation is shown to select for pigmented bacteria in the ambient outdoor atmosphere.
The field experiments showed that the percentage of pigmented bacteria positively correlated with SR activity during clear summer days. In the laboratory the ambient outdoor atmospheric bacteria impacted on culture plates were exposed to simulated SR and a germicidal light. With increased exposure, more nonpigmented bacteria were killed and the percentage of pigmented bacteria gradually increased. These observations suggest an inverse relationship between the atmospheric bacterial survival and the percentage of pigmented bacteria contained therein, thus supporting the notion that pigmentation might provide protection for outdoor atmospheric bacteria from sunlight damage.