Bacillus subtilis spores
Chang et al. 1985 · 254 nm
Test conditions & context
Type Bacterial spore
Medium Water
Test wavelength 254 nm
Particle size 1200 nm
Author Chang et al.
Year 1985
Endosporen, Phosphatpuffer, Niederdruck-Hg 254 nm
UV-C dose–response (D-values)
A D-value is the UV-C dose (in mJ/cm²) needed for a given log-reduction. D90 = 90 % inactivation = 1-log; D99 = 99 % = 2-log; D99.9 = 99.9 % = 3-log, and so on. Values come from the cited study under its specific test conditions.
Reduction log Dose (mJ/cm²)
D90 90 % 1-log 12 mJ/cm²
D99 99 % 2-log 22 mJ/cm²
D99.9 99.9 % 3-log 33 mJ/cm²
Morphology & UV-C resistance
Morphology class Bacterial endospore
Bakterium in Endospore-Form: Mehrschicht-Coat + DPA-Calcium-Komplex + dehydratisiertes Genom. ~100× resistenter als aktive Zelle.
Primary source
Chang et al. (1985). doi.org/10.1128/aem.49.6.1361-1365.1985