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Journal ArticleDOI

Psychrotrophic properties of Listeria monocytogenes

P. O. Wilkins, +2 more
- 01 May 1972 - 
- Vol. 18, Iss: 5, pp 543-551
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TLDR
The increase in the duration of the lag phase of growth with decreasing temperatures was expressed with a hyperbolic curve which indicated an infinite lag time at 3.3C, and this relationship between lag time and temperature would provide a relatively rapid method for estimating minimal temperatures of growth.
Abstract
Listeria monocytogenes grew between 3 and 45C. Growth at 10C was at a rate characteristic of psychrophilic bacteria. The increase in the duration of the lag phase of growth with decreasing temperatures was expressed with a hyperbolic curve which indicated an infinite lag time at 3.3C. If this relationship between lag time and temperature is a general phenomenon, it would provide a relatively rapid method for estimating minimal temperatures of growth. Initial rates for oxygen consumption during glucose metabolism and for uptake of the nonmetabolized sugar, 2-deoxyglucose, had temperature coefficients (10–30C) of about 1.5. Growth at 10C increased the rate and the capacity of 2-deoxyglucose uptake by exponential-phase cells. Uptake and incorporation of L-leucine was relatively rapid at 10C but the temperature coefficients were greater than 2. High temperature coefficients (greater than 2.5) for nicotinamide adenine dinucleotide oxidase and lactic dehydrogenase activity in cell-free preparations indicated th...

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Journal ArticleDOI

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

TL;DR: The application of physical stress to microorganisms is the most widely used method to induce cell inactivation and promote food stability, and such mechanisms of adaptation may be possible to prevent growth of key microorganisms in food products.
Journal ArticleDOI

Predictive modelling of the growth and survival of Listeria in fishery products

TL;DR: It is concluded that predictive models, successfully validated in agreement with defined performance criteria, will be an essential element of exposure assessment within formal quantitative risk assessment.
Journal ArticleDOI

Identification of the Gene Encoding the Alternative Sigma Factor ςB from Listeria monocytogenes and Its Role in Osmotolerance

TL;DR: Cloned the sigB gene and severalrsb genes from L. monocytogenes, encoding homologs of the alternative sigma factor ςB and the RsbUVWX proteins, which govern transcription of a general stress regulon in the related bacterium Bacillus subtilis, observed that the activity of ςBs was uniquely responsive to osmotic upshifting, temperature downshifted, and the presence of EDTA in the growth medium.
Journal ArticleDOI

Growth limits of Listeria monocytogenes as a function of temperature, pH, NaCl, and lactic acid.

TL;DR: The models developed will improve the rigor of microbial food safety risk assessment and provide quantitative data in a concise form for the development of safer food products and processes.
Journal ArticleDOI

Minimum growth temperatures of Listeria monocytogenes and non‐haemolytic listeria

TL;DR: The results indicate that L. monocytogenes grows better than non-haemolytic strains under cold conditions, and the possible role of haemolysins as growth factors is discussed.
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