Biochemical Features of Beneficial Microbes: Foundations for Therapeutic Microbiology

Prospects for Using Bacteriocins of Normal Microbiota in Antibacterial Therapy (Review)

“…Bacteriocins are classified based on several characteristics: the primary molecular structure, molecular weight, the presence of post-translational modifications, physical and chemical properties, the range of antimicrobial activity, the mechanism of antimicrobial action, receptors of target cells and genetic characteristics [7,8,[13][14][15][16][17]. There are three main classes of bacteriocins (Table 1).…”

“…Type A lantibiotics are positively charged elongated screw-shaped peptides with the average molecular weight of 2-4 kDa. The shape and charge of type A molecules facilitate formation of pores in membranes and depolarization of the latter in sensitive bacterial cell species, which leads to their lysis [16]. Type B lantibiotics (2-3 kDa) are globular peptides with negative or neutral charge.…”

“…Subclass IIIb comprises peptides that do not damage the potential of target cell membrane. Target cell death occurs not by cytolysis, but due to ATP outflow [16].…”

“…Bacteriocins are believed to allow indigenous commensal bacteria to occupy several ecological niches as well as establish long-term relationships with other representatives of the biocenosis and commensal relationships with the host [31]. Regulation of a bacteriocin production system may be pheromone-dependent [16,32]. A bacteriocin peptide can function as a pheromone inducing its own production.…”

“…A bacteriocin peptide can function as a pheromone inducing its own production. When bacterial cell density becomes high, the auto-induction loop is activated and bacteriocins are produced in high concentrations [16]. Thus, these peptides are synthesized intensively to affect similar species only when the bacterial density in the biotope is high enough to inhibit the growth of competitive strains.…”