DO ENDOGENOUS PIGMENTS PROTECT BACILLUS SPORES AGAINST UV-RADIATION ?

摘要

The photoprotective potential of bacterial pigments was investigated by irradiating spores of three Bacillus strains differing in their degree of endogenous pigmentation with mono-(254 nm) and polychromatic (UVA, UV-A+B) radiation. Survival was tested as colony forming ability on NB agar after overnight incubation at 37°C. The survival curves showed that the pigment of the red spores of B. atrophaeus DSM 675 efficiently screened against UV-A radiation, but not against UV radiation at shorter wavelengths. It is assumed that the formation of this probably carotene-like pigment has provided an evolutionary advantage as UV-screening substance against environmental UV radiation. These data are also of importance for assessing the likelihood of life on other planets and for planetary protection issues.