Sorption of water by spores, heat-killed spores, and vegetative cells

Several hypotheses explain the heat resistance of bacterial spores in terms of a hydrophobic nature of the spore surface and possibly also the spore interior. The water-sorption properties of naturally hydrated spores which had never been dehydrated before the experiment were studied. The rate of loss of water over P2O5 at 50 °C was measured in a closed chamber by remote weighing with a Cahn electrobalance. The hygroscopicity expressed as percentage of water bound by the sample at aw = 1, 25 °C was as follows.(I) Chemicals:albumin, 70.5; starch, 42.9.(II) Clostridium botulinum 33A, a heat-resistant strain: spores, 47.0; residue (spores heat killed at 121 °C for 30 min), 50.4; exudate (material released from heat-killed spores) 63.1; vegetative cells, 70.3.(III) C. botulinum, type E, strain Beluga, a heat-sensitive strain: spores 62.5; residue, 61.3; exudate, 77.3.It is postulated that molecular masking in the spore is responsible for low binding of water, electrical and chemical inertness, biological dormancy, and high heat resistance of bacterial spores.

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Molecular Physiological Characterization of a High Heat Resistant Spore Forming Bacillus subtilis Food Isolate

Microorganisms ◽

10.3390/microorganisms9030667 ◽

2021 ◽

Vol 9 (3) ◽

pp. 667

Author(s):

Zhiwei Tu ◽

Peter Setlow ◽

Stanley Brul ◽

Gertjan Kramer

Keyword(s):

Bacillus Subtilis ◽

Heat Resistance ◽

Dipicolinic Acid ◽

Laboratory Strain ◽

High Heat ◽

High Heat Resistance ◽

Vegetative Cells ◽

Heat Resistant ◽

Food Isolate ◽

Wet Heat

Bacterial endospores (spores) are among the most resistant living forms on earth. Spores of Bacillus subtilis A163 show extremely high resistance to wet heat compared to spores of laboratory strains. In this study, we found that spores of B. subtilis A163 were indeed very wet heat resistant and released dipicolinic acid (DPA) very slowly during heat treatment. We also determined the proteome of vegetative cells and spores of B. subtilis A163 and the differences in these proteomes from those of the laboratory strain PY79, spores of which are much less heat resistant. This proteomic characterization identified 2011 proteins in spores and 1901 proteins in vegetative cells of B. subtilis A163. Surprisingly, spore morphogenic protein SpoVM had no homologs in B. subtilis A163. Comparing protein expression between these two strains uncovered 108 proteins that were differentially present in spores and 93 proteins differentially present in cells. In addition, five of the seven proteins on an operon in strain A163, which is thought to be primarily responsible for this strain’s spores high heat resistance, were also identified. These findings reveal proteomic differences of the two strains exhibiting different resistance to heat and form a basis for further mechanistic analysis of the high heat resistance of B. subtilis A163 spores.

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Differences and Similarities Among Proteolytic and Nonproteolytic Strains of Clostridium botulinum Types A, B, E and F: A Review

Journal of Food Protection ◽

10.4315/0362-028x-45.5.466 ◽

1982 ◽

Vol 45 (5) ◽

pp. 466-474 ◽

Cited By ~ 28

Author(s):

RICHARD K. LYNT ◽

DONALD A. KAUTTER ◽

HAIM M. SOLOMON

Keyword(s):

Salt Tolerance ◽

Heat Resistance ◽

Low Temperatures ◽

Clostridium Botulinum ◽

High Heat ◽

High Heat Resistance ◽

High Salt Tolerance ◽

Lower Heat ◽

Different Characteristics ◽

Do So

Cultures of Clostridium botulinum types A, B, E and F, which are responsible for human botulism, fall into two groups with different characteristics unrelated to toxin type. These groups differ primarily with respect to proteolysis, but also have different somatic and spore antigens and DNA; the heat resistance of their spores, their growth at low temperatures and their salt tolerance also differ. All known type A strains are proteolytic and all type E strains are non proteolytic, but types B and F have some proteolytic and some nonproteolytic strains. Although proteolytic strains can activate their own toxins, nonproteolytic strains cannot do so and therefore require trypsinization for maximum toxicity. Proteolytic strains are unable to grow at temperatures below 10 C, but have relatively high salt tolerance and spores of high heat resistance. Nonproteolytic strains can grow at 3.3 C and have a lower salt tolerance; their spores have a much lower heat resistance than those of proteolytic strains.

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Clustering rooting for the high heat resistance of some CHNO energetic materials

FirePhysChem ◽

10.1016/j.fpc.2021.02.007 ◽

2021 ◽

Vol 1 (1) ◽

pp. 8-20

Author(s):

Xingyu Huo ◽

Fanfan Wang ◽

Liang Liang Niu ◽

Ruijun Gou ◽

Chaoyang Zhang

Keyword(s):

Heat Resistance ◽

Energetic Materials ◽

High Heat ◽

High Heat Resistance

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P-57: A Transparent Plastic Film having Excellent Optical Properties and High Heat Resistance for Flexible Display Substrates

SID Symposium Digest of Technical Papers ◽

10.1889/1.2433518 ◽

2006 ◽

Vol 37 (1) ◽

pp. 418 ◽

Cited By ~ 1

Author(s):

Yoshiaki Watanabe ◽

Ken-ichi Makita ◽

Yasuyoshi Fujii ◽

Hisanori Okada ◽

Naoto Obara ◽

...

Keyword(s):

Optical Properties ◽

Heat Resistance ◽

High Heat ◽

Plastic Film ◽

High Heat Resistance ◽

Flexible Display ◽

Transparent Plastic

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Palladium-catalyzed silation of adamantanedi- and triol, leading to adamantane–siloxane alternating polymers with high heat resistance

Polymer ◽

10.1016/j.polymer.2007.05.052 ◽

2007 ◽

Vol 48 (15) ◽

pp. 4301-4304 ◽

Cited By ~ 8

Author(s):

Joji Ohshita ◽

Koichi Hino ◽

Ko Inata ◽

Atsutaka Kunai ◽

Takayuki Maehara

Keyword(s):

Heat Resistance ◽

High Heat ◽

High Heat Resistance ◽

Palladium Catalyzed

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A high heat-resistance bioplastic foam with efficient electromagnetic interference shielding

Chemical Engineering Journal ◽

10.1016/j.cej.2017.04.050 ◽

2017 ◽

Vol 323 ◽

pp. 29-36 ◽

Cited By ~ 81

Author(s):

Cheng-Hua Cui ◽

Ding-Xiang Yan ◽

Huan Pang ◽

Li-Chuan Jia ◽

Xin Xu ◽

...

Keyword(s):

Heat Resistance ◽

Electromagnetic Interference ◽

High Heat ◽

High Heat Resistance ◽

Electromagnetic Interference Shielding

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Factors Contributing to Heat Resistance of Clostridium perfringens Endospores

Applied and Environmental Microbiology ◽

10.1128/aem.02629-07 ◽

2008 ◽

Vol 74 (11) ◽

pp. 3328-3335 ◽

Cited By ~ 39

Author(s):

Benjamin Orsburn ◽

Stephen B. Melville ◽

David L. Popham

Keyword(s):

Cell Wall ◽

Heat Resistance ◽

Clostridium Perfringens ◽

Food Poisoning ◽

High Heat ◽

Relative Importance ◽

High Heat Resistance ◽

Factors Affecting ◽

Cooking Process ◽

Determining Factors

ABSTRACT The endospores formed by strains of type A Clostridium perfringens that produce the C. perfringens enterotoxin (CPE) are known to be more resistant to heat and cold than strains that do not produce this toxin. The high heat resistance of these spores allows them to survive the cooking process, leading to a large number of food-poisoning cases each year. The relative importance of factors contributing to the establishment of heat resistance in this species is currently unknown. The present study examines the spores formed by both CPE+ and CPE− strains for factors known to affect heat resistance in other species. We have found that the concentrations of DPA and metal ions, the size of the spore core, and the protoplast-to-sporoplast ratio are determining factors affecting heat resistance in these strains. While the overall thickness of the spore peptidoglycan was found to be consistent in all strains, the relative amounts of cortex and germ cell wall peptidoglycan also appear to play a role in the heat resistance of these strains.

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