No abstract

No abstract

No abstract

No abstract

It has been reported that some lots of commercial media contain substances that inhibit germination of anaerobic spores which can be overcome by adding starch (Foster and Wynne, 1948a). Foster and Wynne ascribed this activity to the unsaturated C18 fatty acids. Halvorson (1950) suggested that this effect may be due to the formation of peroxides from the fatty acids. This investigation was undertaken to test the latter hypothesis. MATERIALS AND METHODS Organisms used. The routine test organism was a putrefactive anaerobe, strain P.A. 3679. Later tests were also run on Clostridium botulinum, strain 7948, Clostridium pasteurianum, strain 7040, Bacillus subtilis, strain of Upjohn Company, and Bacilus stearothermophilus, strain NCA 1518. Preparation of spore suspensions. Anaerobic spores were collected after inoculating Blake bottles containing Yesair's pork infusion agar (Wynne and Foster, 1948) with a suspension of cells containing both spores and vegetative cells. The inoculum for each bottle consisted of 1.5 ml of a 72 hour egg-meat culture (Difco). The bottles were incubated for one week at 37 C in a desiccator which had been evacuated and the air replaced with natural gas. Cells were harvested by washing off the agar surface with sterile distilled water.