Bacillus megateriunm spores labeled with tritiated thymidine were irradiated with monochromatic ultraviolet light, and the DNA of the spores was analvzed for thymine-containing, products. No thymine dimers were observed, but three other thymine photoproducts were found. The unknown products of radiation were produced in vitro by irradiation of DNA that had been dried in the, presence of various salts.

The ultraviolet (UV) photochemistry and photobiology of spores and vegetative cells of Bacillus megaterium have been studied. The response of vegetative cells of B. megaterium appears qualitatively similar to those of Escherichia coli, Micrococcus radiodurans, and Bacillus subtilis with respect to photoproduct formation and repair mechanisms. UV irradiation, however, does not produce cyclobutane-type thymine dimers in the DNA of spores, although other thymine photo-products are produced. The photoproducts do not disappear after photoreactivation, but they are eliminated from the DNA by a dark-repair mechanism different from that found for dimers in vegetative cells. Irradiations performed at three wavelengths produce the same amounts of spore photoproduct and give the same survival curves. Variation of the sporulation medium before irradiation results in comparable alterations in the rate of spore photoproduct production and in survival.

Seroprevalence for anti-HEV IgG was low compared to some European countries, but 1 in 5000 donations was viremic. Viremia was predominantly in younger Irish donors. After Department of Health approval the Irish Blood Transfusion Service implemented individual blood donation HEV RNA screening initially for a 3-year period from January 2016.

Donnellan, J. Edward, Jr. (U.S. Army Natick Laboratories, Natick, Mass.), Ella H. Nags, and Hillel S. Levinson . Chemically defined, synthetic media for sporulation and for germination and growth of Bacillus subtilis . J. Bacteriol. 87: 332–336. 1964.—From 90 to 130 mg (dry weight) of spores (about 1% dark forms) were obtained (per liter) from a chemically defined, synthetic medium, with a two-phase (polyethylene glycol-potassium phosphate) harvest procedure. Optimal sporulation occurred when glucose and glutamic acid were at a concentration of 10 m m in the medium. Ca ++ and Mn ++ were required for sporulation. Heat resistance, dipicolinic acid content, and properties of germination and postgerminative development of spores grown in different concentrations of Ca ++ were investigated. Heat shock did not increase germination of spores derived from the synthetic medium. A synthetic medium, in which spore germination, emergence, and first cell division approached synchrony, was devised.