Highlighted Text:
Show |
Hide
Full text loading...
Chapter 3 : Effects of High Pressure on Bacterial Spores
Author:
Peter Setlow1
VIEW AFFILIATIONS
HIDE AFFILIATIONS
Affiliations:
1: Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, Farmington, CT 06030-3305
Content Type: Monograph
Publication Year:
2008
Category: Applied and Industrial Microbiology
Book DOI:
10.1128/9781555815646
Chapter DOI:
10.1128/9781555815646.ch3
MyBook is a cheap paperback edition of the original book and will be sold at uniform, low price.
Preview this chapter:
Effects of High Pressure on Bacterial Spores, Page 1 of 2
< Previous page | Next page > /docserver/preview/fulltext/10.1128/9781555815646/9781555814236_Chap03-1.gif /docserver/preview/fulltext/10.1128/9781555815646/9781555814236_Chap03-2.gif
Abstract:
High pressures (50 to 800 MPa) were found to inactivate spores many years ago. The killing of spores by pressure is unusual in that very high pressures are often less effective than are lower pressures. The initial germination may be essential for efficient spore killing by pressure, since germinated spores are much more sensitive to stress factors, in particular, heat, than are dormant spores. Consequently, in order to fully understand the effects of high pressures on spores, it is essential to first understand (i) the structure of dormant spores, (ii) some of the factors that contribute to spore resistance, and (iii) the normal mechanism(s) for germination of bacterial spores, as high-pressure germination uses some components of normal spore germination pathways. Spores of Bacillus and Clostridium species have a structure very different from that of growing cells, with a number of layers unique to spores and many spore-specific macromolecules. The nutrients that trigger germination vary in a species- and strain-specific manner, but common ones are L-amino acids, D-sugars, and purine nucleosides. Bacillus subtilis spores have three functional germinant receptors. The GerA receptor responds to L-alanine, while the GerB and GerK receptors together trigger germination with a mixture of L-asparagine (or L-alanine), D-glucose, D-fructose, and K+ ions. Dipicolinic acid (DPA) and other ions that are released early in germination comprise ~25% of the spore core’s dry weight. Germination of spores of some strains, in particular, some Bacillus megaterium strains, is triggered by inorganic salts such as KBr.
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
Figures
Effects of High Pressure on Bacterial Spores
[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/author/10.1128/9781555815646.ch03-1,webId=/content/author/10.1128/9781555815646.ch03-1,properties={foaf_givenname=Peter, foaf_name=Peter Setlow, foaf_surname=Setlow, pub_isAffiliatedWith=[com.pub2web.rdf.cci.facet.ContentItem[id=http://asm.metastore.ingenta.com/content/affiliation/10.1128/9781555815646.ch03-aff1]]}]]
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig01
Figure 1.
Dormant-spore structure. The various layers of the dormant spore are not drawn to scale. Note that the exosporium is not present in spores of many species.
10.1128/9781555815646/f0036-01_thmb.gif
10.1128/9781555815646/f0036-01.gif
Figure 1.
Dormant-spore structure. The various layers of the dormant spore are not drawn to scale. Note that the exosporium is not present in spores of many species.
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig02
Figure 2.
Structure of DPA.
10.1128/9781555815646/f0039-01_thmb.gif
10.1128/9781555815646/f0039-01.gif
Figure 2.
Structure of DPA.
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig03
Figure 3.
10.1128/9781555815646/f0040-01_thmb.gif
10.1128/9781555815646/f0040-01.gif
Figure 3.
Events in various stages of spore germination. This figure is adapted from Fig. 3 in reference 63 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig04
Figure 4.
Rates of DPA release from B. subtilis spores upon treatment with mHP and uHP at various temperatures. Spores of B. subtilis PS533, a derivative of strain 168 carrying plasmid pUB110 (
59
), were incubated at an optical density at 600 nm of 2 in 50 mM Tris-HCl (pH 7.5) and treated for various times and at various temperatures with either 150 MPa (0) or 500 MPa (●). Spore germination was assessed in duplicate samples by monitoring DPA release by measuring the optical density at 270 nm of the supernatant fluid from 1-ml samples centrifuged in a microcentrifuge. The release of DPA in this experiment was linear with time (data not shown). The variation in values for the duplicate samples was ±7% or less. The data for this experiment are from reference
9
.
10.1128/9781555815646/f0044-01_thmb.gif
10.1128/9781555815646/f0044-01.gif
Figure 4.
Rates of DPA release from B. subtilis spores upon treatment with mHP and uHP at various temperatures. Spores of B. subtilis PS533, a derivative of strain 168 carrying plasmid pUB110 ( 59 ), were incubated at an optical density at 600 nm of 2 in 50 mM Tris-HCl (pH 7.5) and treated for various times and at various temperatures with either 150 MPa (0) or 500 MPa (●). Spore germination was assessed in duplicate samples by monitoring DPA release by measuring the optical density at 270 nm of the supernatant fluid from 1-ml samples centrifuged in a microcentrifuge. The release of DPA in this experiment was linear with time (data not shown). The variation in values for the duplicate samples was ±7% or less. The data for this experiment are from reference 9 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig05
Figure 5.
Effects of changes in nutrient receptors on mHP germination. Spores of various isogenic strains of B. subtilis at an optical density at 600 nm of 1 were treated with 150 MPa of pressure at 37°C in 50 mM Tris-HCl (pH 7.5). The germination of duplicate samples of the treated spores was assessed by flow cytometry after staining the spores with the nucleic acid stain Syto 16 (Molecular Probes, Eugene, OR) as described previously (
8
, 67). Dormant-spore nucleic acids are not stained by Syto 16, which only stains fully germinated spores. Symbols represent the various strains of spores used as follows: ○, PS533 (wild type [
59
]); ●, FB72 (
44
) (lacks all three functional germinant receptors); □, PS3301 (lacks the only B. subtilis lipoprotein diacylglycerol transferase [
27
]); ▲, FB68 (lacks GerD [
46
]); and □, PS3476 (
8
) (contains 20-fold-higher levels of the GerA germinant receptor, the major germinant receptor responding to mHP). The variation in values for the duplicate samples was ±5% or less. Data are from references
8
and
46
.
10.1128/9781555815646/f0045-01_thmb.gif
10.1128/9781555815646/f0045-01.gif
Figure 5.
Effects of changes in nutrient receptors on mHP germination. Spores of various isogenic strains of B. subtilis at an optical density at 600 nm of 1 were treated with 150 MPa of pressure at 37°C in 50 mM Tris-HCl (pH 7.5). The germination of duplicate samples of the treated spores was assessed by flow cytometry after staining the spores with the nucleic acid stain Syto 16 (Molecular Probes, Eugene, OR) as described previously ( 8 , 67). Dormant-spore nucleic acids are not stained by Syto 16, which only stains fully germinated spores. Symbols represent the various strains of spores used as follows: ○, PS533 (wild type [ 59 ]); ●, FB72 ( 44 ) (lacks all three functional germinant receptors); □, PS3301 (lacks the only B. subtilis lipoprotein diacylglycerol transferase [ 27 ]); ▲, FB68 (lacks GerD [ 46 ]); and □, PS3476 ( 8 ) (contains 20-fold-higher levels of the GerA germinant receptor, the major germinant receptor responding to mHP). The variation in values for the duplicate samples was ±5% or less. Data are from references 8 and 46 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig06
Figure 6.
Effects of sporulation temperature and loss of DPA on mHP germination. Spores of strain PS533 (wild type [
59
]) were prepared at various temperatures, and spores of strain FB122 (DPA-less [
41
]) were prepared at 37°C. Spores were treated with 150 MPa of pressure at 37°C, and spore germination in duplicate samples was assessed as described in the legend to
Fig. 5.
The symbols for the spores of the strains used are as follows: ○, PS533 spores prepared at 23°C; ●, PS533 spores prepared at 30°C;Δ, PS533 spores prepared at 37°C;□, PS533 spores prepared at 44°C; ▲, FB122 (DPA-less) (
41
) spores prepared at 37°C. The variation in values for the duplicate samples was ±8% or less. Data are from reference
8
.
10.1128/9781555815646/f0046-01_thmb.gif
10.1128/9781555815646/f0046-01.gif
Figure 6.
Effects of sporulation temperature and loss of DPA on mHP germination. Spores of strain PS533 (wild type [ 59 ]) were prepared at various temperatures, and spores of strain FB122 (DPA-less [ 41 ]) were prepared at 37°C. Spores were treated with 150 MPa of pressure at 37°C, and spore germination in duplicate samples was assessed as described in the legend to Fig. 5. The symbols for the spores of the strains used are as follows: ○, PS533 spores prepared at 23°C; ●, PS533 spores prepared at 30°C;Δ, PS533 spores prepared at 37°C;□, PS533 spores prepared at 44°C; ▲, FB122 (DPA-less) ( 41 ) spores prepared at 37°C. The variation in values for the duplicate samples was ±8% or less. Data are from reference 8 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig07
Figure 7.
Effect of loss of germinant receptor function or DPA on uHP germination. Spores of various B. subtilis strains at an optical density at 600 nm of 1 were treated with 500 MPa of pressure at 50°C, and spore germination in duplicate samples was assessed as described in the legend to
Fig. 5.
The symbols for the spores of the strains used are as follows: ○, PS533 (wild type [
56
]); ●, FB72 (lacks all germinant receptors [
44
]);Δ, PS3301 (lacks the lipoprotein diacylglycerol transferase [
27
]); ▲, FB68 (lacks GerD [
42
]); and □, FB122 (DPA-less [
41
]). The variation in values for the duplicate samples was :7% or less. Data are from reference
9
.
10.1128/9781555815646/f0047-01_thmb.gif
10.1128/9781555815646/f0047-01.gif
Figure 7.
Effect of loss of germinant receptor function or DPA on uHP germination. Spores of various B. subtilis strains at an optical density at 600 nm of 1 were treated with 500 MPa of pressure at 50°C, and spore germination in duplicate samples was assessed as described in the legend to Fig. 5. The symbols for the spores of the strains used are as follows: ○, PS533 (wild type [ 56 ]); ●, FB72 (lacks all germinant receptors [ 44 ]);Δ, PS3301 (lacks the lipoprotein diacylglycerol transferase [ 27 ]); ▲, FB68 (lacks GerD [ 42 ]); and □, FB122 (DPA-less [ 41 ]). The variation in values for the duplicate samples was :7% or less. Data are from reference 9 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
/content/10.1128/9781555815646.ch03.ch03fig08
Figure 8.
Effect of inner membrane fatty acid composition and sporulation temperature on uHP spore germination. Spores of various B. subtilis strains prepared at different temperatures were treated at an optical density at 600 nm of 1 with 500 MPa of pressure at 50°C, and spore germination in duplicate samples was assessed as described in the legend to
Fig. 5.
The symbols for the spores of the strains used are as follows: ○, PS533 (wild-type [
59
]) sporulated at 23°C; ●, PS533 sporulated at 37°C; ▲, PS533 sporulated at 44°C; Δ, PS3628 (lacking fatty acid desaturase and containing no unsaturated fatty acids in the spore’s inner membrane [
13
]) prepared at 37°C; and □, PS3624 (has elevated levels of fatty acid desaturase and >10-fold-higher levels of unsaturated fatty acids in the spore’s inner membrane compared to PS533 spores [
13
]) prepared at 37°C. The variation in values for the duplicate samples was ±7% or less. Data are from reference
9
.
10.1128/9781555815646/f0048-01_thmb.gif
10.1128/9781555815646/f0048-01.gif
Figure 8.
Effect of inner membrane fatty acid composition and sporulation temperature on uHP spore germination. Spores of various B. subtilis strains prepared at different temperatures were treated at an optical density at 600 nm of 1 with 500 MPa of pressure at 50°C, and spore germination in duplicate samples was assessed as described in the legend to Fig. 5. The symbols for the spores of the strains used are as follows: ○, PS533 (wild-type [ 59 ]) sporulated at 23°C; ●, PS533 sporulated at 37°C; ▲, PS533 sporulated at 44°C; Δ, PS3628 (lacking fatty acid desaturase and containing no unsaturated fatty acids in the spore’s inner membrane [ 13 ]) prepared at 37°C; and □, PS3624 (has elevated levels of fatty acid desaturase and >10-fold-higher levels of unsaturated fatty acids in the spore’s inner membrane compared to PS533 spores [ 13 ]) prepared at 37°C. The variation in values for the duplicate samples was ±7% or less. Data are from reference 9 .
Citation:
Setlow P.
2008.
Effects of High Pressure on Bacterial Spores,
p 35-52.
In
Michiels C, Bartlett D, Aersten A (ed),
High-Pressure Microbiology.
ASM Press, Washington, DC.
doi: 10.1128/9781555815646.ch3
References
/content/book/10.1128/9781555815646.ch03
1.
Ablett, S.,, A. H. Darke,, P. J. Lillford, and, D. R. Martin. 1999. Glass formation and dormancy in bacterial spores. Int. J. Food Sci. Technol. 34: 59– 69.
2.
D. E., Cortezzo,, Aertsen, A.,, I. Van Opstal,, S. C. Vanmuysen, E. Y. Wuytack, and, C. W. Michiels. 2005. Screening for Bacillus subtilis mutants defective in pressure induced spore germination: identification of ykvU as a novel germination gene. FEMS Microbiol. Lett. 243: 385– 391.
3.
D. E. Cortezzo,, Alberto, F.,, L. Botella,, F. Carlin,, C. Ngyuen-the, and, V. Brouselle. 2005. The Clostridium botulinum GerBA germination protein is located in the inner membrane of spores. FEMS Microbiol. Lett. 253: 231– 235.
4.
D. E. Cortezzo,, Atluri, S.,, K. Ragkousi,, D. E. Cortezzo, and, P. Setlow. 2006. Cooperativity between different nutrient receptors in germination of spores of Bacillus subtilis and reduction of this cooperativity by alterations in the GerB receptor. J. Bacteriol. 188: 28– 36.
5.
Bagyan, I., and, P. Setlow. 2002. Localization of the cortex lytic enzyme CwlJ in spores of Bacillus subtilis. J. Bacteriol. 184: 1289– 1294.
6.
Bartlett, D. H. 2002. Pressure effects on in vivo microbial processes. Biochim. Biophys. Acta 1595: 367– 381.
7.
Bertsch, L. L.,, P. P. Bonsen, and, A. Kornberg. 1969. Biochemical studies of bacterial sporulation and germination. XIV. Phospholipids in Bacillus megaterium. J. Bacteriol. 98: 75– 81.
8.
Black, E. P.,, K. Koziol-Dube,, D. Guan,, J. Wei,, B. Setlow,, D. E. Cortezzo,, D. G. Hoover, and, P. Setlow. 2005. Factors influencing the germination of Bacillus subtilis spores via the activation of nutrient germinant receptors. Appl. Environ. Microbiol. 71: 5879– 5887.
9.
Black, E. P.,, J. Wei,, S. Atluri,, D. G. Cortezzo,, K. Koziol-Dube,, D. G. Hoover, and, P. Setlow. 2007. Analysis of factors influencing the rate of germination of spores of Bacillus subtilis by very high pressure. J. Appl. Microbiol. 102: 65– 76.
10.
Braganza, L. F., and, D. L. Worcester. 1986. Structural changes in lipid bilayers and biological membranes caused by hydrostatic pressure. Biochemistry 25: 7484– 7488.
11.
Cano, R. J., and, M. Borucki. 1995. Revival and identification of bacterial spores in 25- to 40-million-year-old Dominican amber. Science 268: 1060– 1064.
12.
Chirakkal, H.,, M. O’Rourke,, A. Atrih,, S. J. Foster, and, A. Moir. 2002. Analysis of spore cortex lytic enzymes and related proteins in Bacillus subtilis endospore germination. Microbiology 148: 2383– 2392.
13.
Cortezzo, D. E.,, K. Koziol-Dube,, B. Setlow, and, P. Setlow. 2004. Treatment with oxidizing agents damages the inner membrane of spores of Bacillus subtilis and sensitizes the spores to subsequent stress. J. Appl. Microbiol. 97: 838– 852.
14.
Cortezzo, D. E.,, B. Setlow, and, P. Setlow. 2004. Analysis of the action of compounds that inhibit the germination of spores of Bacillus species. J. Appl. Microbiol. 96: 725– 741.
15.
Cortezzo, D. E., and, P. Setlow. 2005. Analysis of factors influencing the sensitivity of spores of Bacillus subtilis to DNA damaging chemicals. J. Appl. Microbiol. 98: 606– 617.
16.
Cowan, A. E.,, D. E. Koppel,, B. Setlow, and, P. Setlow. 2003. A soluble protein is immobile in dormant spores of Bacillus subtilis but is mobile in germinated spores: implications for spore dormancy. Proc. Natl. Acad. Sci. USA 100: 4209– 4214.
17.
Cowan, A. E.,, E. M. Olivastro,, D. E. Koppel,, C. A. Loshon,, B. Setlow, and, P. Setlow. 2004. Lipids in the inner membrane of dormant spores of Bacillus species are immobile. Proc. Natl. Acad. Sci. USA 101: 7733– 7738.
18.
Douki, T.,, B. Setlow, and, P. Setlow. 2005. Photosensitization of DNA by dipicolinic acid, a major component of spores of Bacillus species. Photochem. Photobiol. Sci. 4: 591– 597.
19.
Driks, A. 1999. The Bacillus subtilis spore coat. Microbiol. Mol. Biol. Rev. 63: 1– 20.
20.
Driks, A. 2002. Overview: development in bacteria: spore formation in Bacillus subtilis. Cell. Mol. Life Sci. 59: 389– 391.
21.
Driks, A. 2001. Proteins of the spore core and coat, p. 527– 535. In A. L. Sonenshein,, J. A. Hoch, and, R. Losick (ed.), Bacillus subtilis and Its Closest Relatives: from Genes to Cells. ASM Press, Washington, DC.
22.
Eichenberger, P.,, S. T. Jensen,, E. M. Conlon,, C. van Ooij,, J. Silvaggi,, J. E. Gonzalez-Pastor,, M. Fujita,, S. Ben-Yehuda,, P. Stragier,, J. S. Liu, and, R. Losick. 2003. The “ E regulon and the identification of additional sporulation genes in Bacillus subtilis. J. Mol. Biol. 327: 945– 972.
23.
Errington, J. 1993. Bacillus subtilis sporulation: regulation of gene expression and control of morphogenesis. Microbiol. Rev. 57: 1– 33.
24.
Gerhardt, P., and, R. E. Marquis. 1989. Spore thermoresistance mechanisms, p. 43– 63. In I. Smith,, R. A. Slepecky, and, P. Setlow (ed.), Regulation of Prokaryotic Development. ASM Press, Washington, DC.
25.
Gould, G. W. 1969. Germination, p. 397– 444. In G. W. Gould and, A. Hurst (ed.), The Bacterial Spore. Academic Press, London, England.
26.
Gould, G. W., and, A. J. H. Sale. 1969. Initiation of germination of bacterial spores by hydrostatic pressure. J. Gen. Microbiol. 60: 335– 346.
27.
Igarashi, T.,, B. Setlow,, M. Paidhungat, and, P. Setlow. 2004. Analysis of the effects of a gerF (lgt) mutation on the germination of spores of Bacillus subtilis. J. Bacteriol. 186: 2984– 2991.
28.
Igarashi, T., and, P. Setlow. 2005. Interaction between individual protein components of the GerA and GerB nutrient receptors that trigger germination of Bacillus subtilis spores. J. Bacteriol. 187: 2513– 2518.
29.
Igura, N.,, Y. Kamimura,, M. S. Islam,, M. Shimoda, and, I. Hayakawa. 2003. Effects of minerals on resistance of Bacillus subtilis spores to heat and hydrostatic pressure. Appl. Environ. Microbiol. 69: 6307– 6310.
30.
Jones, C. A.,, N. L. Padula, and, P. Setlow. 2 005. Effect of mechanical abrasion on the viability, disruption and germination of spores of Bacillus subtilis. J. Appl. Microbiol. 99: 1484– 1494.
31.
Kennedy, M. J.,, S. L. Reader, and, L. M. Swierczynski. 1994. Preservation records of micro-organisms: evidence of the tenacity of life. Microbiology 140: 2513– 2529.
32.
Keynan, A., and, Z. Evenchik. 1969. Activation, p. 359– 396. In G. W. Gould and, A. Hurst (ed.), The Bacterial Spore. Academic Press, London, England.
33.
Klobutcher, L. A.,, K. Ragkousi, and, P. Setlow. 2006. The Bacillus subtilis spore coat provides “eat resistance” during phagosomal predation by the protozoan Tetrahymena thermophila. Proc. Natl. Acad. Sci. USA 103: 165– 170.
34.
Knorr, D. 1999. Novel approaches in food-processing technology: new technologies for preserving foods and modifying function. Curr. Opin. Biotechnol. 10: 485– 491.
35.
Leuschner, R. G. K., and, P. J. Lillford. 2003. Thermal properties of bacterial spores and biopolymers. Int.J. Food Microbiol. 80: 131– 143.
36.
Makino, S., and, R. Moriyama. 2002. Hydrolysis of cortex peptidoglycan during bacterial spore germination. Med. Sci. Monit. 8: RA119– RA127.
37.
Margosch, D.,, M. A. Ehrmann,, R. Buckow,, V. Heinz,, R. F. Vogel, and, M. G. Gänzle. 2006. High-pressure-mediated survival of Clostridium botulinum and Bacillus amyloliquefaciens endospores at high temperature. Appl. Environ. Microbiol. 72: 3476– 3481.
38.
Margosch, D.,, M. G. Gänzle,, M. A. Ehrmann, and, R. F. Vogel. 2004. Pressure inactivation of Bacillus endospores. Appl. Environ. Microbiol. 70: 7321– 7328.
39.
Moir, A.,, B. M. Corfe, and, J. Behravan. 2002. Spore germination. Cell. Mol. Life Sci. 59: 403– 409.
40.
N. Munakata,, G. Horneck,, H. J. Melosh, and, P. Setlow. 2000. Resistance of Bacillus endospores to extreme terrestrial and extraterrestrial environments. Microbiol. Mol. Biol. Rev. 64: 548– 572.
41.
Paidhungat, M.,, K. Ragkousi, and, P. Setlow. 2001. Genetic requirements for induction of germination of spores of Bacillus subtilis by Ca 2 +-dipicolinate. J. Bacteriol. 183: 4886– 4893.
42.
Paidhungat, M.,, B. Setlow,, W. B. Daniels,, D. Hoover,, E. Papafragkou, and, P. Setlow. 2002. Mechanisms of initiation of germination of spores of Bacillus subtilis by pressure. Appl. Environ. Microbiol. 68: 3172– 3175.
43.
Paidhungat, M.,, B. Setlow,, A. Driks, and, P. Setlow. 2000. Characterization of spores of Bacillus subtilis which lack dipicolinic acid. J. Bacteriol. 182: 5505– 5512.
44.
Paidhungat, M., and, P. Setlow. 2000. Role of Ger proteins in nutrient and nonnutrient triggering of spore germination in Bacillus subtilis. J. Bacteriol. 182: 2513– 2519.
45.
Paidhungat, M., and, P. Setlow. 2001. Spore germination and outgrowth, p. 537– 548. In A. L. Sonenshein,, J. A. Hoch, and, R. Losick(ed.), Bacillus subtilis and Its Closest Relatives: from Genes to Cells. ASM Press, Washington, DC.
46.
Pelczar, P. L.,, T. Igarashi,, B. Setlow, and, P. Setlow. 2007. Role of GerD in germination of Bacillus subtilis spores. J. Bacteriol. 189: 1090– 1098.
47.
Popham, D. L. 2002. Specialized peptidoglycan of the bacterial endospore: the inner wall of the lockbox. Cell. Mol. Life Sci. 59: 426– 433.
48.
Popham, D. L.,, J. Helin,, C. E. Costello, and, P. Setlow. 1996. Muramic lactam in peptidoglycan of Bacillus subtilis spores is required for spore outgrowth but not for spore dehydration or heat resistance. Proc. Natl. Acad. Sci. USA 93: 15405– 15410.
49.
Raso, J., and, G. Barbosa-Canovas. 2003. Nonthermal preservation of foods using combined processing techniques. Crit. Rev. Food Sci. Nutr. 43: 265– 285.
50.
Raso, J.,, G. Barbosa-Canovas, and, B. G. Swanson. 1998. Sporulation temperature affects initiation of germination and inactivation by high hydrostatic pressure of Bacillus cereus. J. Appl. Microbiol. 85: 17– 24.
51.
Raso, J.,, M. M. Gongora-Nieto, and, B. G. Swanson. 1998. Influence of several environmental factors on the initiation of germination and inactivation of Bacillus cereus by high hydrostatic pressure. Int. J. Food Microbiol. 44: 125– 132.
52.
Redmond, C.,, L. W. Baillie,, S. Hibbs,, A. J. Moir, and, A. Moir. 2004. Identification of proteins in the exosporium of Bacillus anthracis. Microbiology 150: 355– 363.
53.
Rode, L. J., and, J. W. Foster. 1960. The action of surfactants on bacterial spores. Arch. Mikrobiol. 36: 67– 94.
54.
Rode, L. J., and, J. W. Foster. 1960. Mechanical germination of bacterial spores. Proc. Natl. Acad. Sci. USA 46: 118– 128.
55.
Rode, L. J., and, J. W. Foster. 1961. Germination of bacterial spores with alkyl primary amines. J. Bacteriol. 81: 768– 779.
56.
Sale, A. J. H.,, G. W. Gould, and, W. A. Hamilton. 1970. Inactivation of bacterial spores by hydrostatic pressure. J. Gen. Microbiol. 60: 323– 334.
57.
Setlow, B.,, A. E. Cowan, and, P. Setlow. 2003. Germination of spores of Bacillus subtilis with dodecylamine. J. Appl. Microbiol. 95: 637– 648.
58.
Setlow, B.,, E. Melly, and, P. Setlow. 2001. Properties of spores of Bacillus subtilis blocked at an intermediate stage in spore germination. J. Bacteriol. 183: 4894– 4899.
59.
Setlow, B., and, P. Setlow. 1996. Role of DNA repair in Bacillus subtilis spore resistance. J. Bacteriol. 178: 3486– 3495.
60.
Setlow, P. 1994. Mechanisms which contribute to the long-term survival of spores of Bacillus species. J. Appl. Bacteriol. 76: 49S– 60S.
61.
Setlow, P. 1995. Mechanisms for the prevention of damage to the DNA in spores of Bacillus species. Annu. Rev. Microbiol. 49: 29– 54.
62.
Setlow, P. 2001. Resistance of spores of Bacillus species to ultraviolet light. Environ. Mol. Mutagen. 38: 97– 104.
63.
Setlow, P. 2003. Spore germination. Curr. Opin. Microbiol. 6: 550– 556.
64.
Setlow, P. 2006. Spores of Bacillus subtilis: their resistance to radiation, heat and chemicals. J. Appl. Microbiol. 101: 514– 535.
65.
Stecchini, M. L.,, M. Del Torre,, E. Venir,, A. Morettin,, P. Furlan, and, E. Maltini. 2006. Glassy state in Bacillus subtilis spores analyzed by differential scanning calorimetry. Int. J. Food Microbiol. 106: 286– 290.
66.
Tovar-Rojo, F.,, M. Chander,, B. Setlow, and, P. Setlow. 2002. The products of the spoVA operon are involved in dipicolinic acid uptake into developing spores of Bacillus subtilis. J. Bacteriol. 184: 584– 587.
67.
Vepachedu, V. R., and, P. Setlow. 2004. Analysis of the germination of spores of Bacillus subtilis with temperature sensitive spo mutations in the spoVA operon. FEMS Microbiol. Lett. 239: 71– 77.
68.
Vepachedu, V. R., and, P. Setlow. 2005. Localization of SpoVAD to the inner membrane of spores of Bacillus subtilis. J. Bacteriol. 187: 5677– 5682.
69.
Vepachedu, V. R., and, P. Setlow. 2007. Role of SpoVA proteins in release of dipicolinic acid during germination of Bacillus subtilis spores triggered by dodecylamine or lysozyme. J. Bacteriol. 189: 1565– 1572.
70.
Vreeland, R. H.,, W. D. Rosenzweig, and, D. W. Powers. 2000. Isolation of a 250 million-year-old halotolerant bacterium from a primary salt crystal. Nature 407: 897– 900.
71.
Warth, A. D. 1980. Heat stability of Bacillus cereus enzymes within spores and in extracts. J. Bacteriol. 143: 27– 34.
72.
Westphal, A. J.,, B. P. Price,, T. J. Leighton, and, K. E. Wheeler. 2003. Kinetics of size changes of individual Bacillus thuringiensis spores in response to changes in relative humidity. Proc. Natl. Acad. Sci. USA 100: 3461– 3466.
73.
Wuytack, E. Y.,, S. Boven, and, C. W. Michiels. 1998. Comparative study of pressure-induced germination of Bacillus subtilis spores at low and high pressure. Appl. Environ. Microbiol. 64: 3220– 3224.
74.
Wuytack, E. Y.,, J. Soons,, F. Poschet, and, C. W. Michiels. 2000. Comparative study of pressure- and nutrient-induced germination of Bacillus subtilis spores. Appl. Environ. Microbiol. 66: 257– 261.