Thermal inactivation of aerosolized Bacillus subtilis var. niger spores.

Thermal death of Bacillus subtilis var. niger spores on selected lander capsule surfaces.

Dry-heat sterilization of planetary lander capsules requires a knowledge of the thermal resistivity of microorganisms in the environment to which they will be subjected during sterilization of the space hardware. The dry-heat resistance of Bacillus subtilis var. niger spores on various lander capsule materials was determined at 125 C. Eight surface materials were evaluated, including a referenc...

Some Observations on Bacterial Thermal Death Time Curves.

Thermal death rate data were obtained for spores of Clostridium sporogenes P.A. 3679 and Bacillus subtilis var. niger, and for cells of Salmonella senftenberg 775W. The survival curves for P.A. 3679 were approximately linear, but for B. subtilis var. niger or S. senftenberg 775W they were sigmoidal. Decimal reduction times were derived from the regression slopes of the apparent linear portion o...

Ethylene oxide resistance of nondesiccated and desiccated spores of Bacillus subtilis var. niger hermetically sealed in various polymeric films.

The resistance to destruction of spores of Bacillus subtilis var. niger hermetically sealed in various polymeric films and exposed to ethylene oxide with and without relative humidity was determined. The effect of desiccation was also determined. The order of increased resistance to sterilization with regard to type of polymeric film was found to be: polyethylene equal to polyvinyl chloride, le...

Configuration and Base Composition of Deoxyribonucleic Acid from Spores of Bacillus Subtilis Var. Niger.

Microbiological aspects of ethylene oxide sterilization. IV. Influence of thickness of polyethylene film on the sporicidal activity of ethylene oxide.

Spores of Bacillus subtilis var. niger, dried on nonhygroscopic and hygroscopic surfaces, were enclosed in one of four thicknesses of low-density polyethylene film (2, 4, 6, and 20 mils). The surfaces were then placed in a specially designed thermochemical death rate apparatus and exposed to an ethylene oxide concentration of 600 mg/liter (at 54.4 C) and 50% relative humidity. Survival data, in...