Interactions Between Light and Gas Vacuoles in Halobacterium salinarium Strain 5: Effect of Ultraviolet Light.

The potential light shielding by intracellular gas vacuoles in Halobacterium salinarium strain 5 was examined by looking at the ultraviolet light inactivation curves of both wild-type cells and mutants which are defective in the production of gas vacuoles. Whereas strains defective in gas vacuole production were slightly more sensitive to ultraviolet inactivation, no significant differences in ultraviolet sensitivity were seen, indicating that these subcellular inclusion bodies are not effective as light-shielding organelles. In addition, it was shown that ultraviolet light acts as a plasmid-curing agent in Halobacterium.