We use refrigerators in our homes or in the lab that range in temperatures between 0 °C and 7 °C. This temperature range slows microbial metabolism, which slows the growth of microbes significantly and helps preserve food, medical supplies, or lab cultures.

Refrigeration 

Pasteurization is a type of microbial control for food that uses heat but does not sterilize. Pasteurization kills pathogens while maintaining food quality. The process was developed by Louis Pasteur in the 1860s as a way to prevent beer and wine from spoiling. The process is commonly used to kill pathogens in milk, however the products may still spoil since they are not sterile.

Pasteurization

The aseptic technique in the lab uses the dry-heat sterilization method using direct application of high heat, such as sterilizing inoculating loops with the bunsen burner. Incineration at very high temperatures destroys all microbes. Dry heat can also be applied at temperatures up to 170 °C  for extended periods of time  by using a dry-heat sterilizer, such as an oven. However, moist heat is preferred because it penetrates cells better than dry heat.

Dry-Heat Sterilization 

Autoclaves use extreme levels of moist-heat to sterilize contaminated objects. They raise the temperature inside above the boiling point of water to kill any viruses and especially endospores.

Moist-Heat Sterilization

Exposing microbes to either extreme heat or extreme cold is a very effective method of microbial control. Temperature control methods include 
- Sterilization
- Pasteurization
- Refrigeration
- Freezing

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We can use physical methods of microbial control to preserve our food by manipulating the physical environment to inhibit or prevent microbial growth.
Common control methods include:
- moisture control
- radiation
- filtration
- temperature control

Many of these methods kill cells by disrupting membranes, changing their permeability, or denaturing proteins.

Physical Ways to Control Microbial Growth

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Dehydration is used to preserve foods like jerky or seaweed. It works by stripping the cell of water, preventing it from carrying out its metobolic processes. Drying controls microbial growth, however it does not kill all organisms or endospores, which can start to regrow when the water content is restored.

Desiccation

Ionizing radiation and nonionizing radiation can be used to control microbial growth.

Radiation

Temperature Control

Filtration involves physically separating microbes from samples. Air is commonly filtered through high-efficiency particulate air (HEPA) filters that can be found in vacuum cleaners, air-conditioning systems, and air purifiers.

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