Bacteria and Growth Temperature
INTRODUCTION
The environments of Earth include conditions in which physical and chemical extremes make it very difficult for organisms to survive. Conditions that can destroy living cells and biomolecules include high and low temperatures; low amounts of oxygen and water; and high levels of salinity, acidity, alkalinity, and radiation. Examples of extreme environments on Earth are hot geysers and oceanic thermal vents, Antarctic sea ice, and oxygen-depleted rivers and lakes. Organisms that have evolved special adaptations that permit them to live in extreme conditions are called "extremophiles." Photo by: Dmitry Pichugin
"Thermophiles" are microorganisms with optimal growth temperatures between 60 and 108 degrees Celsius, isolated from a number of marine and terrestrial geothermally-heated habitats including shallow terrestrial hot springs, hydrothermal vent systems, sediment from volcanic islands, and deep sea hydrothermal vents.
-Encyclopedia of Environmental Microbiology, 2002. vol.3.
Temperature and bacteria
The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.
Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.
Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at
The environments of Earth include conditions in which physical and chemical extremes make it very difficult for organisms to survive. Conditions that can destroy living cells and biomolecules include high and low temperatures; low amounts of oxygen and water; and high levels of salinity, acidity, alkalinity, and radiation. Examples of extreme environments on Earth are hot geysers and oceanic thermal vents, Antarctic sea ice, and oxygen-depleted rivers and lakes. Organisms that have evolved special adaptations that permit them to live in extreme conditions are called "extremophiles." Photo by: Dmitry Pichugin
"Thermophiles" are microorganisms with optimal growth temperatures between 60 and 108 degrees Celsius, isolated from a number of marine and terrestrial geothermally-heated habitats including shallow terrestrial hot springs, hydrothermal vent systems, sediment from volcanic islands, and deep sea hydrothermal vents.
-Encyclopedia of Environmental Microbiology, 2002. vol.3.
Temperature and bacteria
The lowest temperature at which a particular species will grow is the minimum growth temperature, while the maximum growth temperature is the highest temperature at which they will grow. The temperature at which their growth is optimal is called the optimum growth temperature. In general, the maximum and minimum growth temperatures of any particular type of bacteria are about 30°F (-1°C) apart.
Most bacteria thrive at temperatures at or around that of the human body 98.6°F (37°C), and some, such as Escherichia coli, are normal parts of the human intestinal flora. These organisms are mesophiles (moderate-temperature-loving), with an optimum growth temperature between 77°F (25°C) and 104°F (40°C). Mesophiles have adapted to thrive in temperatures close to that of their host.
Psychrophiles, which prefer cold temperatures, are divided into two groups. One group has an optimal growth temperature of about 59°F (15°C), but can grow at