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[14] [1] Some multicellular eukaryotes can also be metabolically active at sub-zero temperatures, such as some conifers; [15] those in the Chironomidae family are still active at −16 °C. [ 16 ] Psychrophilic algae can tolerate cold temperatures, like this Chlamydomonas green algae growing on snow in Antarctica .
Freezing temperatures curb the spoiling effect of microorganisms in food, but can also preserve some pathogens unharmed for long periods of time. Freezing kills some microorganisms by physical trauma, others are sublethally injured by freezing, and may recover to become infectious.
However, their capacity to resist is also generally lower than of modern bacteria from the same area (black). [1] On Earth, frozen environments such as permafrost and glaciers are known for their ability to preserve items, as they are too cold for ordinary decomposition to take place.
At least six major areas of cryobiology can be identified: 1) study of cold-adaptation of microorganisms, plants (cold hardiness), and animals, both invertebrates and vertebrates (including hibernation), 2) cryopreservation of cells, tissues, gametes, and embryos of animal and human origin for (medical) purposes of long-term storage by cooling to temperatures below the freezing point of water.
Freezing is a phase transition in which a liquid turns into a solid when its temperature is lowered below its freezing point. [ 1 ] [ 2 ] For most substances, the melting and freezing points are the same temperature; however, certain substances possess differing solid-liquid transition temperatures.
8) Once food has been cooked, all the bacteria have been killed The possibility of bacterial growth actually increases after cooking, because the drop in temperature allows bacteria to thrive. 9 ...
In general, freezing or refrigerating prevents virtually all bacteria from growing, and heating food sufficiently kills parasites, viruses, and most bacteria. Bacteria grow most rapidly at the range of temperatures between 40 and 140 °F (4 and 60 °C), called the "danger zone".
The most common organisms that harvest CO 2 to build biomolecules are plants and photosynthetic bacteria. Those particular organisms use the Calvin cycle for their carbon fixation . However, P. fumarii and other similar organisms contain particular enzymes that allow them to harvest CO 2 at temperatures well above those tolerated by plants and ...