Survival of Common Bacteria in Liquid Culture under Carbon Dioxide at High Temperatures

• Published in: Nature (London) 1973-05, Vol.243 (5404), p.242-243
• Main Authors: MOLTON, P., WILLIAMS, JOANN, PONNAMPERUMA, C.
• Format: Article
• Language: English
• Subjects: Bacillus subtilis - growth & development; Bacteria - growth & development; Carbon Dioxide; Enterobacter - growth & development; Escherichia coli - growth & development; Hot Temperature; Humanities and Social Sciences; letter; multidisciplinary; Science; Science (multidisciplinary); Serratia marcescens - growth & development; Space life sciences
• ISSN: 0028-0836; 1476-4687
• DOI: 10.1038/243242a0

WE report results which are at variance with the general belief that high temperatures are necessarily lethal to microorganisms 1 . Escherichia coil B, Aerobacter aerogenes , Bacillus subtilis , and Serratia marcescens were found to survive for 24 h in a CO 2 atmosphere at a temperature of up to 160° C. These organisms were routinely cultured in sterile trypticase soy broth (TSB) medium, and plated on TSB plates containing 1.5% of agar. Cultures were incubated at 37° C on a rotary shaker, sub-cultured every 48 h, and exposed to high temperatures and pressures while in the stationary phase, 48 h after subculturing. One millilitre of each culture was injected into 5 ml. glass tubes, which were then inserted into 75 m stainless steel bombs fitted with a plug and a needle valve, and flushed free of air with commercial grade CO 2 for 30 s before sealing and raising the pressure to up to 20 atm, and enclosing the entire bomb in an oven at 105–160° C for up to 24 h. Pyrene (m.p. 150° C) was liquefied inside such a bomb within 1 h at an oven temperature reading of 150° C, demonstrating effective heat transfer. Control tubes of each culture were maintained at 20° C in air during the experiment, to provide data on viability loss through standing.