Effect of extreme factors on micro-organisms used for the control of the effectiveness of sterilization

Abstract

Survival of micro-organisms used for control of sterilization procedures was studied under conditions simulating the Martian environment (daily temperature change from +20 degrees to -20 degrees in 99.98% CO2 + 0.02% air at 0.13 x 10(-6) N m-2 pressure, with ultraviolet radiation spanning the whole range of the solar spectrum 300-350 MkW cm-2). The test organisms were four strains of Bacillus subtilis and one strain of Bacillus anthracoides, and were inoculated on to four materials, smooth metal, porous plastic, multilayer composition material and powdered limonite. Some organisms survived on all materials, the greatest on the limonite. The resistance of the survivors to disinfectants was the same as that of the original cultures.