The effect of sporulation temperature on sporal characteristics ofBacillus subtilis A
- 91 Downloads
Spores ofBacillus subtilis A were produced at different temperatures (23°–49°C) and examined for a number of sporal characteristics. Spore heat resistance increased with sporulation temperature to 45°C, with spores grown at 49°C showing a dramatic reduction in resistance. Spore crops showed biphasic thermal death curves whether enumerated on germination medium with or without calcium dipicolinate. This strain produces both rough and smooth variants. Of the spores produced at 23°C, 99% were rough, had a density of 1.305, and an average core/core + cortex volume ratio of 0.1838. At 49°C, 99% were smooth, had a density of 1.275, and an average volume ratio of 0.3098. Between these temperatures both spore types were produced. There appeared to be no direct correlation with sporulation temperature, heat resistance, and dipicolinate content. There was an increase in both the magnesium and calcium contents to 45°C with a dramatic reduction at 49°C. The 1.305 density spores had higher calcium and dipicolinate contents than the 1.275 spores, although both spore types showed biphasic thermal death curves. The mechanisms involved in determining which spore type (rough/smooth) is produced at a specific growth temperature is unknown.
KeywordsVolume Ratio Growth Temperature Specific Growth Average Volume Heat Resistance
Unable to display preview. Download preview PDF.
- 1.Algie JE (1983) The heat resistance of bacterial spores and its relationship to the contraction of the forespore protoplast during sporulation. Curr Microbiol 9:173–176Google Scholar
- 8.Gombas DE (1987) Bacterial sporulation and germination. In: Montville TJ (ed) Food microbiology, vol 1. Concepts in physiology and metabolism. Boca Raton, FL: CRC Press, pp 131–155Google Scholar
- 9.Khoury PH, Lombardi SJ, Slepecky RA (1987) Perturbation of the heat resistance of bacterial spores by sporulation temperature and ethanol. Curr Microbiol 15:15–19Google Scholar
- 11.Lindsay JA (1988) Characterization of bacterial spores from high-temperature growth transformants ofBacillus subtilis. Curr Microbiol 16:265–269Google Scholar
- 12.Lindsay JA, Murrell WG (1985) Changes in density of DNA after interaction with dipicolinic acid and its possible role in spore heat resistance. Curr Microbiol 12:329–334Google Scholar
- 14.Lindsay JA, Murrell WG, Warth AD (1985) Spore resístance and the basic mechanism of heat resistance. In: Harris LE, Skopek A (eds) Advances in sterilization of medical products, vol III. Sydney: Lindsay-Yates Press, pp 162–186Google Scholar
- 15.Murrell WG, Warth AD (1965) Composition and heat resistance of bacterial spores. In: Campbell LL, Halvorson HO (eds) Spores III. Ann Arbor, AI: American Society for Microbiology, pp 1–24Google Scholar
- 18.Williams OB, Robertson WJ (1953) Effect of temperature of incubation at which formed on heat resistance of aerobic thermophilic spores. J Bacteriol 67:377–378Google Scholar