They are unicellular microscopic living organisms, which are classified according to:

the shape in Coccus, Bacillus, Spirochete etc.
the composition of their cell wall in Gram+ and in Gram-
the oxygen need in aerobic ones and anaerobic ones
the way to obtain C and energy in autotrophic, phototrophic and chemoautotrophic bacteria etc.

The microorganisms contained in biological activators can be either in vegetative state or in spores, live in isolation or in colonies (UFC), grow, reproduce and attack different nourishing substrates, such as carbohydrates, lipids, proteins, hydrocarbons etc. that can be found in the environment.

1. In the industry, the bacteria are produced on a large scale through fermenters.
2. In the fermentation process, each carefully selected bacterial strain is reproduced. Then two phases follow: purification and stabilization of the natural spores or vegetative cells, which were formed.

The selection takes place per conditioning during the phase of reproduction through specific food linked to the metabolism characteristics, which are typical of each strain. This process strengthens and specializes the degradation in certain substrates.

The bacteria produce specific enzymes to degrade the organic substance (fat, proteins, sugar, starch, cellulose...) and transform those complex substances into water and carbon dioxide.
they reproduce and live until the food exhaustion (organic material), then their life cycle ends.
they work where the chemical and mechanical systems are not effective.
they are biodegradable and harmless to humans, animals and environment.