We know more about bacteria than any other microoganisms common in soil.
Bacteria are single-cell organisms, the simplest and smallest forms of life.
They multiply by elongating and dividing into half and are therefore often called fission fungi. It is a simple process and under the right conditions, very rapid. A new organism may develop in twenty or thirty minutes easily. This gives them the unlimited capacity to increase in numbers and this is important in soils. It allows certain groups quickly to assume their normal functions under favorable conditions, even though their numbers were originally small.