Calculation of mass and water content between the core, cortex, and coat ofBacillus stearothermophilus spores

Algie, J. E.; Watt, I. C.

doi:10.1007/bf01577136

Cited by 5 publications

(7 citation statements)

References 9 publications

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“…In consideration of equation 1, then, 11wV = PWV* + RTln(PwvIPwv*) + mwvgh (4) where P,,,* is the saturation vapor pressure in equilibrium with pure liquid water at atmospheric pressure and at the same temperature as the system under consideration and m,,, is the mass per mole of water vapor, which is the same as the mass per mole of water, mw. Therefore, the water potential of water vapor in a gas phase such as air is T'I', which is expressed as W, = (RTIV,) ln (%RH/100) + p,gh (5) where p,, is the density of water. A convenient relationship used for the estimation of matric water potentials in such systems can be derived from equation 4:…”

Section: Matric Water Potentialmentioning

confidence: 99%

“…The water contents of bacterial spores are considered to be difficult to measure but appear to be lower than those of their corresponding vegetative cells. The spore, spore coat, cortex, core, and protoplasm of Bacillus stearothermnophilus had values in the range of 0.21 to 0.58 g of H20 g (dry weight)-1, and the aw of the cortex was 0.83 (5). Akinetes (Dauerzellen) are resting stages (differentiated cells) that are produced by certain species of heterocystous cyanobacteria (136).…”

Section: Water In Enzymatic Reactionsmentioning

confidence: 99%

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Desiccation tolerance of prokaryotes.

Potts

1994

Microbiological Reviews

841

598

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Section: Matric Water Potentialmentioning

confidence: 99%

Section: Water In Enzymatic Reactionsmentioning

confidence: 99%

Desiccation tolerance of prokaryotes.

Potts

1994

Microbiological Reviews

841

598

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“…Other anhydrobiotic microorganisms include cyanobacteria (Potts 1999) and the radiotolerant Deinococcus radiodurans (Mattimore & Battista 1996). However, Potts (1994) has, with justification, rejected the acceptance of bacterial spores and akinetes into the anhydrobiotic family on the grounds that they contain too much water, and certainly values for the residual water content in the range 0.21-0.58 g H 2 O g dry weight 21 could allow some continuation of biological processes (Clegg 1978;Algie & Wyatt 1984). In the animal kingdom, members of three invertebrate phyla-tardigrades (Wright 2001), nematodes (Perry 1999) and rotifers-are capable of anhydrobiosis at all developmental stages, including the adult form.…”

Section: Anhydrobiosis (A) Latent Lifementioning

confidence: 99%

Resurrecting Van Leeuwenhoek's rotifers: a reappraisal of the role of disaccharides in anhydrobiosis

Tunnacliffe

Lapinski

2003

Phil. Trans. R. Soc. Lond. B

184

136

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In 1702, Van Leeuwenhoek was the first to describe the phenomenon of anhydrobiosis in a species of bdelloid rotifer, Philodina roseola. It is the purpose of this review to examine what has been learned since then about the extreme desiccation tolerance in rotifers and how this compares with our understanding of anhydrobiosis in other organisms. Remarkably, much of what is known today about the requirements for successful anhydrobiosis, and the degree of biostability conferred by the dry state, was already determined in principle by the time of Spallanzani in the late 18th century. Most modern research on anhydrobiosis has emphasized the importance of the non-reducing disaccharides trehalose and sucrose, one or other sugar being present at high concentrations during desiccation of anhydrobiotic nematodes, brine shrimp cysts, bakers' yeast, resurrection plants and plant seeds. These sugars are proposed to act as water replacement molecules, and as thermodynamic and kinetic stabilizers of biomolecules and membranes. In apparent contradiction of the prevailing models, recent experiments from our laboratory show that bdelloid rotifers undergo anhydrobiosis without producing trehalose or any analogous molecule. This has prompted us to critically re-examine the association of disaccharides with anhydrobiosis in the literature. Surprisingly, current hypotheses are based almost entirely on in vitro data: there is very limited information which is more than simply correlative in the literature on living systems. In many species, disaccharide accumulation occurs at approximately the same time as desiccation tolerance is acquired. However, several studies indicate that these sugars are not sufficient for anhydrobiosis; furthermore, there is no conclusive evidence, through mutagenesis or functional knockout experiments, for example, that sugars are necessary for anhydrobiosis. Indeed, some plant seeds and micro-organisms, like the rotifer, exhibit excellent desiccation tolerance in the absence of high intracellular sugar concentrations. Accordingly, it seems appropriate to call for a re-evaluation of our understanding of anhydrobiosis and to embark on new experimental programmes to determine the key molecular mechanisms involved.

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“…The current view assumes that the main role is played by the inner membrane, which, in dormant endospores, is largely immobile and greatly reduces water permeation, , thus preserving the core from being hydrated. On the other hand, the subsequent layer, the cortex, is believed to be hydratable and can accommodate a large proportion of the water content of the endospore when the endospore is fully hydrated (note that the external layer, the coat, is permeable to water and, when the endospore is hydrated, tends to show lower water content than the cortex). , …”

Section: Resultsmentioning

confidence: 99%

“…In recent years a significant effort has been made to develop micro/nanotechniques able to examine the internal hydration properties of endospores at the single endospore level. These techniques allow providing direct answers to this problem not subject to the averaging associated with traditional population endospore studies. − The single endospore techniques used for hygroscopic studies include high-resolution secondary ion mass spectrometry (NanoSIMS), confocal Raman microspectroscopy, fluorescence redistribution after photobleaching microscopy (FRAP), , automated scanning optical microscopy, and microsystem techniques, such as single particle levitation and suspended microchannel resonators . In spite of the valuable results obtained by the above-mentioned techniques, they still suffer from some inherent limitations, including the lack of spatial resolution (nanoscale), of being able to work in situ on a broad range of RH levels on a given endospore in a nondestructive way, or of having sensitivity to the internal hydration properties.…”

mentioning

confidence: 99%

Internal Hydration Properties of Single Bacterial Endospores Probed by Electrostatic Force Microscopy

et al. 2016

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We show that the internal hydration properties of single Bacillus cereus endospores in air under different relative humidity (RH) conditions can be determined through the measurement of its electric permittivity by means of quantitative electrostatic force microscopy (EFM). We show that an increase in the RH from 0% to 80% induces a large increase in the equivalent homogeneous relative electric permittivity of the bacterial endospores, from ~4 up to ~17, accompanied only by a small increase in the endospore height, of just a few nanometers. These results correlate the increase of the moisture content of the endospore with the corresponding increase of environmental RH. 3D finite element numerical calculations, which include the internal structure of the endospores, indicate that the moisture is mainly accumulated in the external layers of the endospore, hence preserving the core of the endospore at low hydration levels. This mechanism is different from what we observe for vegetative bacterial cells of the same species, in which the cell wall at high humid atmospheric conditions is not able to preserve the cytoplasmic region at low hydration levels. These results show the potential of quantitative EFM under environmental humidity control to study the hygroscopic properties of small scale biological (and non-biological) entities and to determine its internal hydration state. A better understanding of nano-hygroscopic properties can be of relevance in the study of essential biological processes and in the design of bio-nanotechnological applications. KEYWORDSElectrostatic Force Microscopy, bacterial endospores, relative humidity, electric permittivity, nano-hygroscopicity.

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Calculation of mass and water content between the core, cortex, and coat ofBacillus stearothermophilus spores

Cited by 5 publications

References 9 publications

Desiccation tolerance of prokaryotes.

Desiccation tolerance of prokaryotes.

Resurrecting Van Leeuwenhoek's rotifers: a reappraisal of the role of disaccharides in anhydrobiosis

Internal Hydration Properties of Single Bacterial Endospores Probed by Electrostatic Force Microscopy

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