Macromolecular Sieving by the Dormant Spore of
            <i>Bacillus cereus</i>

Scherrer, René; Beaman, T C

doi:10.1128/jb.108.2.868-873.1971

Cited by 30 publications

(23 citation statements)

References 14 publications

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“…In other words, it appeared that ions from the environment could enter part of the spore volume. This finding agrees with the results of permeability studies (14) permeability data available for B. cereus spores, and the shift in relaxation frequency shows that the outer structure is dielectrically effective even 8 though it is permeable to small ions. For the Dorrnant outer membrane to be an insulator in this con-Dormant text, its conductance would have to be less than (a~~i o10mho/m (6).…”

Section: Insofar As Environmental Ions Can Penetratesupporting

confidence: 90%

“…Although previous interpretations of permeability and dielectric data (5,14) have viewed the penetrated structures as the coat-outer membrane-cortex complex, the exosporium cannot be ruled out as the dielectrically effective membrane. Spore dimensions in electron micrographs (1,18) suggest that the space between the exosporium and coats of B. cereus is somewhat less than half of the volume of the entire spore.…”

Section: Insofar As Environmental Ions Can Penetratementioning

confidence: 91%

See 1 more Smart Citation

Dielectric properties of native and decoated spores of Bacillus megaterium

Carstensen¹,

Marquis²,

Child³

et al. 1979

J Bacteriol

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Section: Insofar As Environmental Ions Can Penetratesupporting

confidence: 90%

Section: Insofar As Environmental Ions Can Penetratementioning

confidence: 91%

Dielectric properties of native and decoated spores of Bacillus megaterium

Carstensen¹,

Marquis²,

Child³

et al. 1979

J Bacteriol

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“…The spore membrane is relatively impermeable (Nicholson et al 2000). Indeed, the size of molecules that can pass through the coat has been estimated to be eight for B. cereus (Scherrer et al 1971;Driks 1999) and 2 Kda for B. megaterium (Nishihara et al 1989;Driks 1999). Thus, DiBAC 4 (3), a molecule of 516AE6 dalton (B.…”

Section: Discussionmentioning

confidence: 99%

Assessment of bacterial endospore viability with fluorescent dyes

Laflamme

Lavigne

Ho³

et al. 2004

J Appl Microbiol

109

102

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Aim: To validate three fluorescence viability assays designed primarily for vegetative cells on pure Bacillus endospores. Methods and Results: Purified fresh and gamma-irradiated Bacillus endospores (Bacillus cereus, B. coagulans and two strains of B. subtilis) were used. The viability assays were: 5-cyano-2,3-diotolyl tetrazolium chloride (CTC) to test respiratory activity and early germination, DiBAC 4 (3) and Live/Dead BacLight to measure membrane energization and permeabilization, respectively. Gamma irradiation treatment completely eliminated spore culturability and was used as negative control. The untreated spores showed respiratory activity after 1 h of incubation and this was characteristic of almost 100% of spores after 24 h. The membrane potential assessment gave no answer about spore viability. A lower proportion of untreated spores had permeabilized membrane compared with gamma-irradiated spores using Live/Dead BacLight (P < 0AE02). Conclusion: It is possible to use CTC and Live/Dead BacLight to rapidly test endospore viability and evaluate the proportion of spores in a preparation that could not be recovered with plate count. Significance and Impact of the Study: This study shows that fluorescence tests could be applied to assess viability in potentially pathogenic Bacillus spore preparations within 1 h.

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“…Figure 1 shows the pH profiles of the colloidal charge of carboxymethyl (CM)and phospho (P)-cellulose, representative colloids containing carboxylic and phosphoric groups, respectively in their molecules, indicating the reaction specificity of the positive colloids; GCh reacts only with strong acidic groups such as phosphate, and MGCh reacts with all negatively charged groups including carboxylate. The values obtained by titrating the spores with these colloids are interpreted as the surface charges of the spores because the colloids, having an average molecular weight of about 100,000 (II), cannot penetrate into the spores (10).…”

Section: Methodsmentioning

confidence: 99%

Studies on the Bacterial Spore Coat: IX. The Role of Surface Charge in Germination of Bacillus megaterium Spores

Nishihara

Yoshimoto

Kondo

1981

Microbiology and Immunology

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The surface charge of Bacillus megaterium QM B 1551 spores was estimated to be negative, -0.2 and -0.4 t-teq(mg by colloidal titration using glycol chitosan (GCh) and methylglycol chitosan (MGCh), respectively, as positive colloids. MGCh, which reacts with all of the negatively charged groups including carboxylate, inhibited the second stage of the germination to result in semirefractile spores, but GCh, which reacts only with strong acidic groups such as phosphate, did not. The spores produced in a medium with limited phosphate had coats with low phosphate content and carried less negative charge, and they were induced to germinate with 0.4 msr KN03, which is one-tenth of the minimum concentration required for the germination of the control spores. A similar increase in germinability was observed in spores incubated with calcium acetate.. These results suggest that the role of the surface charge in germination is as follows. Strong acidic groups (such as phosphate) in the coat may block the action of ionic germinants and act as a barrier against the initiation of ionic germination. Positively charged compounds (such as calcium) may compensate for this blocking effect. Weak acidic groups (such as carboxylate) may be involved in the later stage of germination.The spore coat, composed of proteins with phosphate, is the outermost layer of Bacillus megaterium spores (5), and is the first contact of the spores with information in their environment, such as germinants. Therefore, the coat has been a subject for the study of the properties of spores, especially the mechanism of germination. On the spore surface are exposed many reactive groups of the coat, including such components as sulfhydryl, hydroxyl, carboxylic, phosphoric, and amino groups. We reported that sulfhydryl and hydroxyl groups might playa role in the recognition of a germinant in the initiation of germination (14). We have now studied the role of the negatively charged groups of the spore surface in germination by using positive colloids for the colloid titration.

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Macromolecular Sieving by the Dormant Spore of Bacillus cereus

Cited by 30 publications

References 14 publications

Dielectric properties of native and decoated spores of Bacillus megaterium

Dielectric properties of native and decoated spores of Bacillus megaterium

Assessment of bacterial endospore viability with fluorescent dyes

Studies on the Bacterial Spore Coat: IX. The Role of Surface Charge in Germination of Bacillus megaterium Spores

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