To study the effect of incubation temperature, preincubated sterile culture medium in screw-capped test tubes was inoculated and incubated in a water bath adjusted to the desired temperature. The capacity to grow under anaerobic conditions was determined in freshly prepared broth in screw-capped test tubes. The medium was cooled, inoculated, covered with a 3- cm layer of sterile mineral oil, sealed tightly, and incubated at 37°C. For all tests, the inoculum was 1 drop of culture grown for 24 h at 37°C in modified MRS broth. For determining oxidase (38) and catalase activities, and for morphological studies, the organisms were cultured on the modified medium solidified with 1.5% agar.