Bacteriocins are the matters of protein nature, produced by bacteria of many species that inhibit the development of related organisms. Other antibiotics (see) Bacteriocins have a narrow range. At present, there are over 20 types of bacteriocins, and the number continues to grow. Property to produce inhibitory substances inherent in the majority of species of bacteria. B. are named by their generic names microbe-producer: pesticide - the plague microbe, vibriosis - cholera Vibrio, stafilokokkami - Staphylococcus, tuberculosis - tuberculous mycobacteria, magaziny - You. B. megaterium, colicins - enterobacteria.
Synthesis of bacteriocins controlled by genetic elements belonging to the class AMISOM (see),- bacteriocenozei factors. The ability to synthesize bacteriocins may be transferred to bacteria of the same or closely related species by co-cultivation by conjugation [see Genetics (Genetics of bacteria)]. Bacteria, producing B. make up a small part of the population; the rest retain this ability potentially unlimited number of generations. To activate bacteriologico population can influence of ultraviolet rays and other inducing factors (some dyes and other). Microbial cell, producing bacteriocins, dies in most cases without lysis (see Bacteriosis)observed at the effect of bacteriophage. Due to the destruction of part of a population of microbes and suppress the growth of other bacteria that need the same nutrient substrates, is provided by primary development of bacteriocinogenic populations in their natural habitat.
Most of bacteriocins are released to the environment in which it is cultivated organism, and can be accumulated in large quantities. In dense media presence B. is defined in characteristic zones of delay of growth of sensitive bacteria - indicator strains. The size of the area shows the activity B. and the speed of its diffusion into agar (Fig).
Accumulated in the liquid environment bacteriocins after separation from microbial mass by centrifugation and processing chloroform for sterilization can be used as antibacterial drugs limited spectrum. In conditionally pathogenic or pathogenic microbes bacteriologist may be an additional factor of pathogenicity.

The lack of growth of the indicator culture (dark zone) around microcolony bacteria, producing bacteriocins.