Isolation and characterization of omnitherms and facultative anaerobes from Cape Canaveral soil samples

In a bacterial population profile of interplanetary spacecraft environments based upon temperature and oxygen requirements, several isolates demonstrated the ability to grow over a temperature range from 3 degrees C to 55 degrees C, and most grew aerobically and anaerobically. Because of the adaptability of these organisms, they may be of significance to planetary contamination. To verify that these were actively growing in this range of temperatures, they were streaked onto trypticase soy agar (TSA) and incubated at the extreme temperatures (3 degrees C and 55 degrees C). Isolated colonies were transferred to fresh TSA and immediately incubated at the opposite extreme temperatures. Almost all of the isolates grew quite well at both temperatures. Because these have been subcultured numerous times and still possess the ability to grow over a broad temperature range, this appears to be a stable characteristic. Many of these isolates possess the ability to grow anaerobically at 3, 32 and 55 degrees C. All of these organisms are sporeformers, and data are presented concerning their heat resistance and biochemical activity.