The optimum growth temperature of most microorganisms is 25℃ ~ 37℃; In the optimum growth temperature range, the growth rate of microorganisms increases with the increase of temperature; When the optimum growth temperature is exceeded, the growth rate of microorganisms drops sharply, which is due to the irreversible damage of intracellular protein and nucleic acid. Low temperature can inhibit the growth and reproduction of bacteria and produce toxins.

Basic conditions for bacterial growth and reproduction: adequate nutrients, energy and suitable environment (temperature, pH, gas conditions, osmotic pressure) are essential conditions for bacterial growth and reproduction.

Extended data

Bacteria have many different metabolic patterns. Some bacteria only need carbon dioxide as a carbon source and are called autotrophs. Those who get energy from light through photosynthesis are called photosynthetic autotrophs. Those who rely on oxidized compounds for energy are called chemoautotrophs. Other bacteria rely on organic carbon as carbon source, which is called heterotrophic bacteria. ?

Photosynthetic autotrophic bacteria include cyanobacteria, which are the oldest known organisms and may play an important role in producing oxygen in the earth's atmosphere. Other photosynthetic bacteria carry out some processes that do not produce oxygen. Include green sulfur bacteria, green non-sulfur bacteria, purple sulfur bacteria, purple non-sulfur bacteria and Heliobacter. ?

Nutrients required for normal growth include nitrogen, sulfur, phosphorus, vitamins and metal elements such as sodium, potassium, calcium, magnesium, iron, zinc and cobalt.