Mesophile

Source: Wikipedia, the free encyclopedia.

A mesophile is an

gram-negative. Oxygen requirements for mesophiles can be aerobic or anaerobic. There are three basic shapes of mesophiles: coccus, bacillus, and spiral
.

Habitat

The habitats of mesophiles can include

pathogens are mesophiles, as are most of the organisms comprising the human microbiome
.

Mesophiles vs. extremophiles

Mesophiles are the opposite of extremophiles. Extremophiles that prefer cold environments are termed psychrophilic, those preferring warmer temperatures are termed thermophilic or thermotropic and those thriving in extremely hot environments are hyperthermophilic. A genome-wide computational approach has been designed by Zheng, et al. to classify bacteria into mesophilic and thermophilic.[3]

Adaptations

All bacteria have their own optimum environmental surroundings and temperatures in which they thrive. Many factors are responsible for a given organism's optimal temperature range, but evidence suggests that the expression of particular genetic elements ([alleles]) can alter the temperature-sensitive phenotype of the organism. A study published in 2016 demonstrated that mesophilic bacteria could be genetically engineered to express certain alleles from psychrophilic bacteria, consequently shifting the restrictive temperature range of the mesophilic bacteria to closely match that of the psychrophilic bacteria.[4]

Due to the less stable structure of mesophiles, it has reduced flexibility for

protein synthesis.[5] Mesophiles are not able to synthesize proteins in low temperatures. It is more sensitive to temperature changes, and the fatty acid composition of the membrane does not allow for much fluidity.[6] Decreasing the optimal temperature of 37 °C to 0 °C to 8 °C leads to a gradual decrease in protein synthesis. Cold-induced proteins (CIPs) are induced during low temperatures, which then allows cold-shock proteins (CSPs) to synthesize. The shift back to the optimal temperature sees an increase, indicating that mesophiles are highly dependent on temperature.[7] Oxygen availability also affects microorganism growth.[8]

There are two explanations for thermophiles being able to survive at such high temperatures whereas mesophiles can not. The most evident explanation is that thermophiles are believed to have cell components that are relatively more stable than the cell components of mesophiles which is why thermophiles are able to live at higher temperatures than mesophiles.[9] "A second school of thought, as represented by the writings of Gaughran (21) and Allen (3), believes that rapid resynthesis of damaged or destroyed cell constituents is the key to the problem of biological stability to heat."[9]

Oxygen requirements

Due to the diversity of mesophiles, oxygen requirements greatly vary.

acids, alcohol, or gases. If there is oxygen present, it will use aerobic respiration instead. Obligate anaerobes cannot grow in the presence of oxygen. Aerotolerant anaerobes
can withstand oxygen.

Roles

Microorganisms play an important role in

Psychrotrophic bacteria
contribute to dairy products spoiling, getting mouldy or going bad due to their ability to grow at lower temperatures such as in a refrigerator.

Examples

Some notable mesophiles include

Thiobacillus novellus, Streptococcus pyogenes, and Streptococcus pneumoniae
. Different types of diseases and infections typically have pathogens from mesophilic bacteria such as the ones listed above.

Listeria monocytogenes

Listeria monocytogenes is a gram-positive bacterium. It is closely related to Bacillus and Staphylococcus. It is a rod-shaped, facultative anaerobe that is motile by peritrichous

flagella. L. monocytogenes motility is limited from 20 °C to 25 °C.[12] At the optimal temperature, it loses its motility. This bacterium is responsible for listeriosis which derives from contaminated food.[12]

Staphylococcus aureus

Staphylococcus aureus was first identified in 1880.[13] It is responsible for different infections stemming from an injury. The bacterium overcomes the body's natural mechanisms. Long lasting infections of S. aureus includes pneumonia, meningitis, and osteomyelitis. S. aureus is commonly contracted in hospital settings.[13]

Escherichia coli

Escherichia coli is a gram-negative, rod-shaped facultative anaerobic bacterium that does not produce

gut of living organisms.[15] E. coli has many capabilities such as being a host for recombinant DNA and being a pathogen.[15]

See also

References

  1. ^ Willey, Joanne M., Linda Sherwood, Christopher J. Woolverton, and Lansing M. Prescott. Prescott, Harley, and Klein's Microbiology. New York: McGraw-Hill Higher Education, 2008. Print.
  2. ISBN 978-3-642-40872-4
    , retrieved 2022-05-22
  3. PMID 21172057
    .
  4. PMID 26773080
    .
  5. ^ Vijayabaskar, Mahalingam S. et al. "Construction of Energy Based Protein Structure Networks: Application in the Comparative Analysis of Thermophiles and Mesophiles" Biophysical Journal, Volume 98, Issue 3, 387a
  6. doi:10.1111/j.1745-4549.1993.tb00733.x
    .
  7. ^ Perrot, F., Hébraud, M., Junter, G.-A. and Jouenne, T. "Protein synthesis in Escherichia coli at 4°C. Electrophoresis." 2000, 21: 1625–1629. doi:10.1002/(SICI)1522-2683(20000501)21:8<1625::AID-ELPS1625>3.0.CO;2-4
  8. ^ Sinclair, N. A.; Stokes, J. L. " ROLE OF OXYGEN IN THE HIGH CELL YIELDS OF PSYCHROPHILES AND MESOPHILES AT LOW TEMPERATURES." The Journal of Bacteriology, 1963, Vol. 85(1), p.164 [Peer Reviewed Journal]
  9. ^
    PMID 13488883
    .
  10. ^ Ferroni, G.D., Kaminski, J.S. "Psychrophiles, psychrotrophs, and mesophiles in an environment which experiences seasonal temperature fluctuations." Canadian Journal of Microbiology, 1980, 26:1184-1191, 10.1139/m80-198
  11. ^ Johnson, Mark. "Mesophilic and Thermophilic Cultures Used in Traditional Cheesemaking." Cheese and Microbes. Washington: ASM Publishing. 2014. Web.
  12. ^ a b Magalhã£Es, R. (2014). Listeria monocytogenes. 450-461.
  13. ^ a b Todd, E. (2014). Staphylococcus Aureus. 530-534
  14. ^ a b Robinson, Richard K.. (2000). Encyclopedia of Food Microbiology, Volumes 1-3 - Escherichia Coli. Elsevier. Online version available at: http://app.knovel.com/hotlink/pdf/id:kt0051LGG3/encyclopedia-food-microbiology/escherichia-coli
  15. ^ a b Robinson, Richard K.. (2000). Encyclopedia of Food Microbiology, Volumes 1-3 - Escherichia Coli. Elsevier. Online version available at: http://app.knovel.com/hotlink/pdf/id:kt0051K7I1/encyclopedia-food-microbiology/ecology-bacteria-escherichia-3
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