Reproduction of bacteria
Like other single-celled organisms, bacteria multiply by fission. Each bacterium divides into two daughter bacteria, which grow rapidly and divide again. Under favorable conditions, cell division in many bacteria can occur every 20 to 30 minutes.
With such a rapid reproduction, one bacterium could give in a day (provided that all emerging individuals survive) offspring with a total mass of 1,800,000 kg, and the offspring of one bacterium in 5 days could fill all the seas and oceans on Earth.
However, this does not happen in nature, since most bacteria quickly die under the influence of sunlight, during drying, lack of food, heating to 65 – 100 ° C, under the influence of disinfectants, etc.
Under unfavorable conditions (with a lack of food, moisture, sharp changes in temperature), the cytoplasm of the bacterial cell, shrinking, moves away from the mother membrane, rounds and forms a new, denser membrane inside it on its surface. Such a bacterial cell is called a spore (from the Greek word for “spore” – seed).
Spores of some bacteria persist for a very long time in the most unfavorable conditions. They can withstand drying, heat and frost, and do not die immediately, even in boiling water. Spores are easily carried by wind, water, etc. There are many of them in the air and soil. In favorable conditions, the spore germinates and becomes a vital bacterium.