Effects of Escherichia coli B/R ORNL membranes on the growth and characterization of Peptostreptococcus anaerobius and the induction of mutants by means of cesium-137 ionizing radiation

Current methodologies used in the production, screening and characterization of bacterial mutants poses inherent problems when these methods are applied to strict anaerobes. Inclusion of sterile stable Escherichia coli B/r ORNL membranes in the cell suspension fluid during irradiation resulted in the scavenging of oxygen radicals and peroxides produced during exposure. This decreases bacterial death caused by these factors and increases the possibility that the radiation will produce changes in the chromosome. The P2 membranes eliminate the need for cysteine-HCI which acts as a radioprotective agent and allow aerobic culturing techniques to be applied to strict anaerobes in mutation studies. P. anaerobius VPInumber 4330 was exposed to Cesium-137 gamma radiation. Cell survival, biochemical activities and changes in antibiotic resistance as effected by the inclusion of the P2 membranes were determined on the prototype and the isolated variants. Resistance parameters were established, with and without the presence of the P2 membranes, using the Kirby-Bauer disk diffusion method, the Minimal Inhibitory Concentration (MIC) determination and Gas Liquid Chromatography (GLC). The P2 membranes were also used to investigate changes in tyrosine degradation and cell sensitivity to sodium polyanethol sulfonate, both of which are used in P. anaerobius identification