The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of <i>Clostridium sporogenes</i> (PA 3679/S<sub>2</sub>)

Roberts, T. A.; Ingram, M.

doi:10.1111/j.1365-2672.1966.tb03507.x

Cited by 30 publications

(19 citation statements)

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“…The inhibitory effect of NaCl (1–10%) in the recovery medium on heat‐injured spores was earlier shown for several Clostridium and Bacillus strains, although sensitivity to NaCl may differ between strains (Roberts and Ingram 1966; Roberts et al . 1966; Hutton et al .…”

Section: Discussionmentioning

confidence: 85%

“…The extent of spore injury could be established by studying spore recovery on optimal media and media containing antimicrobials, such as organic acids, sodium chloride or nitrite. Sublethally‐injured spores appear to have an increased sensitivity to these antimicrobials (Roberts and Ingram 1966; Roberts et al . 1966; Foegeding and Busta 1981; Blocher and Busta 1983; Cook and Pierson 1983; Faille et al .…”

Section: Introductionmentioning

confidence: 99%

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Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

2001

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Aims: To assess the in¯uence of sporulation media on heat resistance, and the use of stress recovery media to measure preservation injury of spores of ®ve representative spoilage bacilli. Methods and Results: Bacillus spores prepared on nutrient agar supplemented with Ca 2+ , Mg 2+ , Mn 2+ , Fe 2+ and K + were more heat-resistant than spores obtained from nutrient agar with Mn 2+ . This increased heat resistance correlated with a decrease in the protoplast water content as determined by buoyant density sedimentation. The degree of preservation injury severity could be assessed on media containing NaCl at moderate pH and organic acids at acid pH. Ca-DPA, K + or proline were added to the recovery media to demonstrate that heat probably caused injury to both spore germination and the outgrowth system. Signi®cance and Impact of the Study 2 : The metal content of sporulation media can strongly effect the validity of preservation resistance studies. The distinctive recovery media developed here can be relevant for assessing and comparing new preservation technologies.

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Section: Discussionmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

2001

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“…It is recognized that the addition of sodium chloride to the recovery medium causes both a reduction of viability of cells and a lower apparent D value of the spores (7,12,16,22,32). However, as far as we know, the influence of the water activity of the recovery medium and the types of depressors used upon the estimated D values of spores had never been investigated.…”

Section: Discussionmentioning

confidence: 99%

“…Acidification of the recovery medium causes also a reduction in spore recovery and in apparent heat resistance (11,17,33,34,41). The addition of sodium chloride in the recovery medium causes effects similar to those observed with acidification: a reduction of the viability of cells and a lower apparent D value (7,12,22,30,32). However, as far as we know, the effect of reducing the water activity of the recovery medium by depressors other than sodium chloride has never been investigated.…”

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confidence: 91%

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Effect of Water Activities of Heating and Recovery Media on Apparent Heat Resistance of Bacillus cereus Spores

Coroller¹,

Leguérinel²,

Mafart³

2001

Appl Environ Microbiol

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Spores of Bacillus cereus were heated and recovered in order to investigate the effect of water activity of media on the estimated heat resistance (i.e., the D value) of spores. The water activity (ranging from 0.9 to 1) of the heating medium was first successively controlled with three solutes (glycerol, glucose, and sucrose), while the water activity of the recovery medium was kept near 1. Reciprocally, the water activity of the heating medium was then kept at 1, while the water activity of the recovery medium was controlled from 0.9 to 1 with the same depressors. Lastly, in a third set of experiments, the heating medium and the recovery medium were adjusted to the same activity. As expected, added depressors caused an increase of the heat resistance of spores with a greater efficiency of sucrose with respect to glycerol and glucose. In contrast, when solutes were added to the recovery medium, under an optimal water activity close to 0.98, a decrease of water activity caused a decrease in the estimated D values. This effect was more pronounced when sucrose was used as a depressor instead of glycerol or glucose. When the heating and the recovery media were adjusted to the same water activity, a balancing effect was observed between the protective influence of the solutes during heat treatment and their negative effect during the recovery of injured cells, so that the overall effect of water activity was reduced, with an optimal value near 0.96. The difference between the efficiency of depressors was also less pronounced. It may then be concluded that the overall protective effect of a decrease in water activity is generally overestimated.It has been recognized that the heat resistance of bacterial spores depends on the medium in which the spores are heated. The maximum thermostability of most microorganisms was found in the range of between 0.2 and 0.4 water activity (1,3,27,28,29). In typical ranges of water activities which are found in foodstuffs (a w Ͼ 0.8), the heat resistance of microorganisms generally increases at decreasing water activities. However, the apparent effect of the water activity of the medium on spores or vegetative cells is complicated by the specific effect of solutes which are used as depressors. It is generally agreed that the occurrence of such solutes in the medium reduces the heat resistance of microorganisms. This antagonism between the protective effect of an increase in water activity and the opposite specific effect of depressors can explain conflicting data from various authors.The influence of salt on the thermostability of microorganisms is disputed and depends on the heated type of microorganism. Some authors found no effect of the sodium chloride concentration on the heat resistance of bacteria (9,29,32,42). Others observed a reduced heat resistance of microorganisms at increasing salt concentrations (7,12,22,23). On the contrary, a protective effect of salt was found in several studies (6,14,26,35,38,39,40). Corry (14) deduced from his data that sodium chloride had a therm...

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The microbiological role of nitrite and nitrate

Roberts¹

1975

J Sci Food Agric

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In unheated products nitrite, together with sodium chloride and the pH value, contributes to the selection of the bacteria which grow during storage. Nitrate per se is generally believed to serve only as a reservoir for nitrite, but the commercial use of nitrate-free cover brines in the Wiltshire bacon industry shows that such a reservoir is not always essential. Nitrate sometimes reduced the growth rate of bacteria in experimental Wiltshire collar bacon, but was of no benefit in back bacon. The clostridia occurring naturally in the bacon grew to higher numbers in collar cured without nitrate than that cured with nitrate. Clostridium botulinum (types A and B) was detected in these bacons, but did not grow in the bacon. In heated products the growth of surviving bacteria is controlled by the interaction of several factors including pH, sodium chloride, storage temperature and sodium nitrite or a substance derived from it upon heating. Further experiments are warranted to investigate the effects of dextrose, nitrate, ascorbate and polyphosphate.

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The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of Clostridium sporogenes (PA 3679/S₂)

Abstract: Summary. In 3% and 6% (w/v) sodium chloride solutions the heat resistances of spores of Clostridium sporogenes were the same as in water. Heating to give a 0.1% survival rendered the surviving spores more sensitive to inhibition by sodium chloride in the recovery medium.

Cited by 30 publications

References 6 publications

Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

Effect of Water Activities of Heating and Recovery Media on Apparent Heat Resistance of Bacillus cereus Spores

The microbiological role of nitrite and nitrate

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The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of Clostridium sporogenes (PA 3679/S2)

Abstract: Summary. In 3% and 6% (w/v) sodium chloride solutions the heat resistances of spores of Clostridium sporogenes were the same as in water. Heating to give a 0.1% survival rendered the surviving spores more sensitive to inhibition by sodium chloride in the recovery medium.

Cited by 30 publications

References 6 publications

Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

Effect of sporulation and recovery medium on the heat resistance and amount of injury of spores from spoilage bacilli

Effect of Water Activities of Heating and Recovery Media on Apparent Heat Resistance of Bacillus cereus Spores

The microbiological role of nitrite and nitrate

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Product

Resources

About

The Effect of Sodium Chloride on Heat Resistance and Recovery of Heated Spores of Clostridium sporogenes (PA 3679/S₂)