Answer: Bacteria can be grouped based on the temperature on which their growth is favorable.
Thermophiles: A thermophile can be defined as an organism that can grow a high temperatures. The temperature ranges from 41 to 122 °C. They are found in hydro thermal vents and are found to be oldest on earth.
Mesophiles: It can be defined as organism which best grows in the temperature that is neither hot nor cold. The temperature ranges in between 20 to 45 °C.
Psychrophiles: It can be defined as the organism that tend to survive in colder conditions which ranges in between −20 °C to +10 °C.
Most of bacteria that constitute in food spoilage are mesophiles because food is usually kept at room temperatures which favors its growth.