pH stress can cause cell elongation in Bacillus and Clostridium species: a research note

Everis, Linda; Betts, Gail

doi:10.1016/s0956-7135(00)00017-7

Cited by 36 publications

(19 citation statements)

References 5 publications

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“…Protein synthesis was also necessary to return the cytoplasmic pH to normal (Hall and others 1995). Morphological changes such as cell elongation in Bacillus polymyxa and Clostridium tyrobutyricum as a stress response to suboptimal pH conditions has been observed (Everis and Betts 2001). Once the cells are put back into favorable conditions, the cells reverted and gave a rapid apparent increase in cell numbers.…”

Section: Other Effects Of Low Ph Stressmentioning

confidence: 98%

Adaptation of Microorganisms to Cold Temperatures, Weak Acid Preservatives, Low pH, and Osmotic Stress: A Review

Beales

2004

Comp Rev Food Sci Food Safe

610

361

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The application of physical stress to microorganisms is the most widely used method to induce cell inactivation and promote food stability. To survive, microorganisms have evolved both physiological and genetic mechanisms to tolerate some extreme physical conditions. This is clearly of significance to the food industry in relation to survival of pathogens or spoilage organisms in food. In some microorganisms, the "cold shock response" has been observed in response to abrupt changes to lower temperatures. This results in the production of specific sets of proteins (cold shock proteins), the continued synthesis of proteins involved in transcription and translation, and the repression of heat shock proteins. The addition of weak acid preservatives (for example, sorbates, benzoates) also induces a specific pattern of gene expression (for example, 'Acid Tolerance Response'), which is likely to be required for optimal adaptation of bacteria to weak acid preservatives and low pH. The primary mode of the antimicrobial action of low pH is to reduce the internal cell pH (pHi) below the normal physiological range tolerated by the cell, leading to growth inhibition. Survival mechanisms involve maintaining pH homeostasis, and this is achieved by a combination of passive and active mechanisms. Microorganisms adapt to osmotic stress by accumulating non-ionic or compatible solutes such as trehalose, glycerol, sucrose, and mannitol. These compatible solutes help balance the osmotic pressure and help preserve protein function inside the cells. By understanding and controlling such mechanisms of adaptation, it may be possible to prevent growth of key microorganisms in food products.2 COMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY-Vol. 3, 2004 CRFSFS: Comprehensive Reviews in Food Science and Food Safety organisms will still be metabolically active and viable if transferred to favorable conditions (Busta 1978;Abbiss 1983;Ray 1986). Preservation techniques are designed to prevent microbial growth in processed foods, by disrupting the internal environment of the cell such that growth is no longer possible.Temperature, water activity, addition of preservatives, and pH are all parameters used to inhibit or destroy microorganisms and their spores and are also used as an aid for food preservation (Marechal and others 1999). Other parameters such as heat and bacteriostatic and bactericidal agents are also used in food preservation; they are not included in this review, but have been reviewed extensively (Lindquist 1986;Hendrick and Hartl 1993;Abee and Wouters 1999;Brul and Coote 1999). Some microorganisms have evolved and are capable of rapidly adapting to a continuously changing environment, thus developing tolerance or resistance to increased "doses" of particular stresses. Different types of organism possess different inherent resistances and susceptibilities to stress. For instance, Gram-negative bacteria are regarded as being more sensitive to cold shock, chilling, and freezing than Gram-positive bacteria (Straka ...

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Section: Other Effects Of Low Ph Stressmentioning

confidence: 98%

Adaptation of Microorganisms to Cold Temperatures, Weak Acid Preservatives, Low pH, and Osmotic Stress: A Review

Beales

2004

Comp Rev Food Sci Food Safe

610

361

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“…For example, authors refer that stress factors such as salinity, nutrient depletion, temperature, pH and atmosphere affect bacterial cell shape, suggesting that morphological changes are correlated to adaptive mechanisms that allow bacteria to prolong survival under adverse conditions (Mattick et al . , ,b; Everis and Betts ; Alonso et al . ; Shi and Xia ; Alterman et al .…”

Section: Introductionmentioning

confidence: 99%

Changes in adhesion ability of Aeromonas hydrophila during long exposure to salt stress conditions

et al. 2012

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Aims Stressful environmental conditions influence both bacterial growth and expression of virulence factors. In the present study, we evaluated the influence of NaCl on Aeromonas hydrophila adhesiveness at two temperatures. This agent is often involved in clinical cases; however, its pathogenic potential is still not fully understood. Methods and Results Bacteria were grown in presence of 1·7%, 3·4%, 6·0% NaCl over a 188 day period and then reinoculated in fresh Nutrient Broth with incubation at 4 and 24°C. Bacterial adhesiveness was tested on Hep‐2 cells, and specimens were processed for light, scanning and transmission electron microscopy. Adhesive capacity decreased over time with an increase in reduction percentages depending on NaCl concentrations. At 1·7% NaCl, the reduction was apparently temporary and adhesiveness rapidly recovered in revitalized bacteria, while 3·4%, 6·0% NaCl seemed to be detrimental. Normal, elongated and filamentous bacteria retained adhesiveness capability, although with reduced expression, while in spherical cells, this property seemed to be lost or dramatically reduced. Conclusions Our study shows that high osmolarity plays a significant role in adhesion inhibition, therefore having possible implications in the pathogenesis of the infections by Aer. hydrophila. Significance and Impact of the Study This study intends to give a contribution to a better understanding of the pathogenic role of this bacterium whose pathogenicity is still under debate.

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“…Clostridium and L. monocytogenes (EVERIS;BETTS, 2001;BADONI;JONES, 2007;HAZELEGER;DALVOORDE;BEUMER, 2006;McMULLEN, 2003;KIEBOOM et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

Elongated cells of Listeria monocytogenes in biofilms in the presence of sucrose and bacteriocin-producing Leuconostoc mesenteroides A11

Ratti¹,

Gomes²,

Martinez³

et al. 2010

Ciênc. Tecnol. Aliment.

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pH stress can cause cell elongation in Bacillus and Clostridium species: a research note

Cited by 36 publications

References 5 publications

Adaptation of Microorganisms to Cold Temperatures, Weak Acid Preservatives, Low pH, and Osmotic Stress: A Review

Adaptation of Microorganisms to Cold Temperatures, Weak Acid Preservatives, Low pH, and Osmotic Stress: A Review

Changes in adhesion ability of Aeromonas hydrophila during long exposure to salt stress conditions

Elongated cells of Listeria monocytogenes in biofilms in the presence of sucrose and bacteriocin-producing Leuconostoc mesenteroides A11

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