Why are bacterial cultures kept at 37 degrees and in which phase of cell cycle should cultured cells be at the time of sub culturing?
Hello,
Not all bacteria are grown at 37 degrees, it depends on their optimal growth temperature, and each bacteria has its optimal growth temperature.
There are, for example, bacteria which have an optimal growth temperature of 28 degrees.
For pre-cultures, they must be in the exponential phase of growth.
Dear Dr. Rk Naresh
Human pathogens generally multiply best at temperatures similar to those of the human host (35°C – 37°C). So, pathogenic microorganisms are incubated at 37°C, as 37°C is normal body temperature of humans so the pathogens grow well at this temperature.
After the lag phase, bacterial cells enter the exponential or log phase. This is the time when the cells are dividing by binary fission and doubling in numbers after each generation time. So, the best time to subculture cells is between the log phase and the stationary phase, before the cells reach confluence.
Best.
In general, when a cell line reaches about 80% confluence, the cells must be subculture to ensure proper growth and health. A confluence of 80% means that 80% of the culture vessel surface is covered with cells. For pre-cultures; they must be in the exponential phase of growth. Human pathogens generally multiply best at temperatures similar to those of the human host (35°C – 37°C). So, pathogenic microorganisms are incubated at 37°C, as 37°C is normal body temperature of humans so the pathogens grow well at this temperature. But, if you keep it longer at 37*C or room temperature, the bacteria may start dying (depends upon the type of bacteria), because the bacteria will replicate continuously in this condition, and those dead bacteria may release toxic substance in the culture media and that can affect the growth of other live bacteria. Temperature is a key physicochemical factor that affects the bacterial environment, making incubators indispensable in clinical laboratories. Human pathogens generally multiply best at temperatures similar to those of the human host (35°C – 37°C). You should subculture your cells if you observe a rapid drop in pH (>0.1 – 0.2 pH units) with an increase in cell concentration. Insect cells should be subculture when they are in the log phase, before they reach confluence.
Why are bacterial cultures kept at 37 degrees?
37 degrees Celsius is the optimal temperature for the growth of most human pathogens. This is because the human body maintains a core temperature of around 37 degrees Celsius. When bacterial cultures are kept at this temperature, they are able to grow and divide rapidly. This is important for clinical microbiology laboratories, which need to be able to isolate and identify bacteria from patient samples quickly and accurately.
In addition, 37 degrees Celsius is also the optimal temperature for many biochemical reactions that are used to identify and characterize bacteria. For example, the Gram stain, which is one of the most common methods for bacterial identification, is performed at 37 degrees Celsius.
In which phase of cell cycle should cultured cells be at the time of sub culturing?
Cultured cells should be in the log phase of the cell cycle at the time of sub culturing. The log phase is the phase of the cell cycle when cells are growing and dividing rapidly. During this phase, cells have the highest metabolic activity and are most resistant to stress.
Sub culturing cells in the log phase ensures that the cells will be able to attach to the new culture dish and start growing rapidly. If cells are sub cultured in a different phase of the cell cycle, they may not attach to the new culture dish as well, or they may not start growing as rapidly.
This can lead to a decrease in the overall yield of cells, or it can lead to the selection of cells that are more resistant to stress. In the case of clinical microbiology laboratories, sub culturing cells in the log phase is important for ensuring that the cells are viable and that they can be accurately identified and characterized.
To determine the optimal time for sub culturing cells, it is important to monitor their growth using a light microscope or a cell counter. Once the cells have reached a density of approximately 70-90% confluence, they are ready to be sub cultured.
Psychrophiles grow best in the temperature range of 0–15 °C whereas psychrotrophs thrive between 4°C and 25 °C. Mesophiles grow best at moderate temperatures in the range of 20 °C to about 45 °C. Pathogens are usually mesophiles. Thermophiles and hyperthemophiles are adapted to life at temperatures above 50 °C. Bacterial cultures are incubated at a certain temperature to encourage their growth in the mixtures. Incubation can be done at optimal temperatures because different bacteria grow at different temperatures. Nutrients and proper temperature will help them to achieve the lag phase. The air in the incubator was kept at 37 degrees Celsius, the same temperature as the human body, and the incubator maintained the atmospheric carbon dioxide and nitrogen levels necessary to promote cell growth. At this time, incubators also began to be used in genetic engineering. Temperature is a key physicochemical factor that affects the bacterial environment, making incubators indispensable in clinical laboratories. Human pathogens generally multiply best at temperatures similar to those of the human host (35°C – 37°C). These bacteria can grow at temperatures between 5°C and 60°C, which is known as the temperature danger zone. The fastest rate of growth is at around 37°C, the temperature of the human body. For pre-cultures, they must be in the exponential phase of growth. Human pathogens generally multiply best at temperatures similar to those of the human host (35°C – 37°C). So, pathogenic microorganisms are incubated at 37°C, as 37°C is normal body temperature of humans so the pathogens grow well at this temperature. You should subculture your cells if you observe a rapid drop in pH (>0.1 – 0.2 pH units) with an increase in cell concentration. Insect cells should be subcultured when they are in the log phase, before they reach confluency. Lag phase: Cells recover from sub-cultivation, attach to the surface and start to spread. Log phase: Cells grow exponentially and double at a characteristic rate defining the cell line's doubling time slows or even stops. Death phase: Cells start dying and detach from the surface.
37 degrees Celsius is the optimal temperature for the growth of most human pathogens. This is because the human body maintains a core temperature of around 37 degrees Celsius. When bacterial cultures are kept at this temperature, they are able to grow and divide rapidly. Since E. coli evolved in your colon, it isn't a stretch to find that the optimum temperature for its growth is around 37 degrees Celsius. Bacteria that thrive at these temperatures are called mesophiles. A mesophile is able to grow and divide between 10 degrees Celsius and 45 degrees Celsius. Incubate the bacteria at 32°C to 37°C under microaerophilic conditions. Growth usually occurs after 48 hours, although some strains may take several days to grow. Bacteria can live in hotter and colder temperatures than humans, but they do best in a warm, moist, protein-rich environment that is pH neutral or slightly acidic. There are exceptions, however. Some bacteria thrive in extreme heat or cold, while others can survive under highly acidic or extremely salty conditions. Bacterial culture is a method that allows the multiplication of bacterial cells in or on a culture medium under controlled laboratory conditions. The exact conditions required for optimal replication will depend on the target bacterial species.
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