A BIOFILM USED AS ULTRAVIOLET-DOSIMETER
Article first published online: 2 JAN 2008
Photochemistry and Photobiology
Volume 55, Issue 3, pages 389–395, March 1992
How to Cite
Quintern, L. E., Horneck, G., Eschweiler, U. and Bücker, H. (1992), A BIOFILM USED AS ULTRAVIOLET-DOSIMETER. Photochemistry and Photobiology, 55: 389–395. doi: 10.1111/j.1751-1097.1992.tb04252.x
- Issue published online: 2 JAN 2008
- Article first published online: 2 JAN 2008
- Received 29 March 1991; accepted 6 August 1991
Abstract— A UV-dosimeter has been developed for routine measurements which mainly weights the various components of the spectrum in relation to their damaging effects on a microorganism. For this purpose a biofilm was constructed, comprising dried spores of Bacillus subtilis (wild-type or DNA repair defective strain), immobilized on transparent polyester plastic sheets. After irradiation, the biofilm was incubated in a growth medium. The proteins, synthesized by the immobilized microorganisms after spore germination and several cell divisions, were stained and determined by photometry, giving a measure of the biological activity. The ”biologically effective dose“ was determined from a calibration curve. It reflects the dose equivalent to that of the calibration source producing the same effect.
The UV-response of the biofilm is additive and follows the reciprocity law in the range of fluence rates investigated. The response is nearly independent of temperature within the range of -20°C to +70°C as well as of humidity between about 37 and 80% relative humidity. Storage for up to 9 months at <70% relative humidity and room temperature does not significantly influence the viability of the spores.