Sensitizing Bacterial Spores to Heat by Exposing Them to Ultraviolet Light

Abstract

The spores of Bacillus cohaerens and B. albolactis and a member of the mesentericus group were sensitized to heat by exposing them in aqueous suspensions to cold quartz-mercury radiation, or to the rays passing through the quartz and fluorite windows of a H discharge tube; those spores of moderate and high resistance to light and heat were most affected. Many spores which survived heat or u.-v. were thereby sensitized to that particular influence; the number of spores sensitized to heat by light was less than the number sensitized to light by light and the number sensitized to heat by light was less than the number sensitized to heat by heat. Rays between 1250 and 1600 A were more effective in sensitizing spores to heat than those transmitted by quartz.