The Effect of Temperature on Bacterial Growth

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Bacteria, in general, grows in a wide range of temperatures. But specific bacteria strains generally require more narrow temperature ranges in order to grow effectively.

University Study of Temperature on Bacteria

  • In a study done by students at James Madison University, the Escherichia coli (E. Coli) and Bacillus megaterium were put through three high temperatures: 80 degrees F, 98 degrees F and 108 degrees F. Both bacteria grew best at the lowest of the temperatures.

Different Temps For Different Bacteria

  • Bacteria are grouped into three categories for optimum temperature-based growth: psychrophilic, mesophilic and thermophilic. Phileo in Greek means "lover of."

    Psychro- means low temperature. Psychrophilic bacteria are bacteria that grow best in low temperatures, such as 32 to 68 degrees F. Examples of psychrophilic bacteria are basic soil bacteria like arthrobacter and psychrobacter. Arthrobacter is bacteria that helps neutralize the poisonous effects of some pesticides and nicotine, but psychrobacter is a cause of diseases like meningitis.

    Meso- means "moderate or middle." Mesophilic bacteria grow best in lukewarm to cool warm temperatures, or 77 to 113 degrees F.

    Thermophilic (thermo- means "hot or heat") bacteria grow best in warm to hot temperatures, or 122 to 158 degrees F. Examples of thermophilic bacteria are Bacillus flavothermus and Thermus aquaticus. Bacillus flavothermus is a spore-forming bacteria found in soils. Thermus aquaticus lives in hot water. It is an important bacteria that helps humans, plants and animals code, recode and reproduce DNA and RNA with precision.

    Hyper means "above." Hyperthermophilic bacteria will grow in very hot temperatures, or 158 to 230 degrees F.

Extreme Freezing

  • Extreme freezing can generally stop bacterial growth and/or kill bacteria. The colder the temperature the fewer bacteria that can survive and grow. That is why keeping food cool retards spoilage.

Extreme Heating

  • Extreme heating over well over the boiling point of water is required to stop bacterial growth and/or kill bacteria altogether. A temperature that is higher than the highest optimum temperature for a hyperthermophilic bacterium will stop the reproduction of that bacterium and any other. That is why doctors sterilize surgical instruments with extremely high heat.

Real Life Applications

  • You body will try to spike its temperature--in other words, run a fever-- to rid itself of disease-causing bacteria. Humans can only spike a fever so high, however, so antibiotics are needed in some instances to kill the harmful bacteria.

    When a meat product is on display in a supermarket, the heat of the display lighting can increase bacterial growth and promote a more rapid decay of the meat.

    Hospitals normally keep their central air conditioning systems turned on low because cooler temperatures inhibit the growth of most harmful bacteria.



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