Chemical States of Bacterial Spores: Dry-Heat Resistance
Gordon Alderton,Neva Snell +1 more
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TLDR
In this paper, a method of testing spore resistance to dry heat has been designed to minimize artifacts resulting from change of chemical state during the test, effects of water vapor activity, incomplete recovery of spores from the test container and clumping of spores.Abstract:
Mature bacterial spores can be manipulated by chemical pretreatments between states sensitive and resistant to dry heat. The two chemical forms of the spore differ in dry-heat resistance by about an order of magnitude. Log survivor curves for each chemical state were approximately straight lines. The temperature dependence of dry-heat resistance for each chemical state was similar to that usually found for dry-heat resistance. A method of testing spore resistance to dry heat has been designed to minimize artifacts resulting from (i) change of chemical state during the test, (ii) effects of water vapor activity, (iii) incomplete recovery of spores from the test container and clumping of spores. Implications of the existence of different chemical resistance states for experimental strategy and testing of dry-heat resistance are discussed.read more
Citations
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Journal ArticleDOI
Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments.
TL;DR: The molecular laboratory model of spore resistance mechanisms is summarized and attempts to use the model as a basis for exploration of the resistance of spores to environmental extremes both on Earth and during postulated interplanetary transfer through space as a result of natural impact processes.
Journal ArticleDOI
Spores of Bacillus subtilis: their resistance to and killing by radiation, heat and chemicals
TL;DR: Factors important in spore chemical resistance vary with the chemical, but include: (i) the spore coat proteins that likely react with and detoxify chemical agents; (ii) the relative impermeability of theSpore's inner membrane that restricts access of exogenous chemicals to the spur core; (iii) the protection of spore DNA by its saturation with α/β‐type SASP; and (iv) DNA repair for agents that kill spores via DNA damage
Journal ArticleDOI
Chemical states of bacterial spores: heat resistance and its kinetics at intermediate water activity.
Gordon Alderton,Neva Snell +1 more
TL;DR: A method for measuring heat resistance at intermediate humidity was designed to provide direct and unequivocal control of water vapor concentration with quick equilibration, maintenance of known spore state, and dispersion of spores singly for valid survivor counting.
Journal ArticleDOI
Chemical manipulation of the heat resistance of Clostridium botulinum spores.
Gordon Alderton,K A Ito,J K Chen +2 more
TL;DR: The chemical forms of Clostridium botulinum 62A and 213B were prepared, and their heat resistances were determined in several heating media, including some low-acid foods, to find the resistant spore form of both types that can be sensitized to heating at the normal pH of the food.
References
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Journal ArticleDOI
The heat resistance of bacterial spores at various water activities.
W. G. Murrell,W. J. Scott +1 more
TL;DR: The heat resistance of the spores of six species of bacteria varied with water activity at which the spores were heated, although the magnitude of the changes differed greatly between species.
Journal ArticleDOI
Behavior of bacterial spores in aqueous polymer two-phase systems.
L. E. Sacks,Gordon Alderton +1 more
TL;DR: The high selectivity of the upper phase for spores makes possible the preparation of greatly enriched concentrates of spores directly from complex natural materials, such as soil and feces.
Journal ArticleDOI
Heat resistance of bacterial spores at various water activities.
W G Murrell,W J Scott +1 more
TL;DR: Studies of spores having a wide range of heat resistance in phosphate buffer have shown that these differences in heat resistance largely disappear when the spores are heated in a substantially dry state.
Journal ArticleDOI
Base exchange and heat resistance in bacterial spores.
Gordon Alderton,Neva Snell +1 more
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Chemical states of bacterial spores: heat resistance and its kinetics at intermediate water activity.
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