Biological Methods for Microbial Control

Biological agents control microbial growth through predation, competition, and secretions.

Predatory bacteria like Bdellovibrio control populations of Salmonella and E. coli by invading their periplasm, multiplying inside, and then releasing offspring that continue eliminating the target bacteria. Myxococcus species control plant pathogenic fungi by secreting enzymes that kill them.

Probiotics, such as Lactobacillus species, enhance gut health by outcompeting pathogens like E. coli for intestinal adhesion sites, helping prevent infections.

Bacteriophage sprays target and kill specific bacterial pathogens. Endolysins, which are purified bacteriophage proteins, eradicate gram-positive pathogens.

Antibiotics are powerful antibacterials. Bacteria-derived tetracyclines inhibit protein synthesis, and fungi-derived penicillin disrupts peptidoglycan cell walls.

Microbial enzymes such as depolymerases degrade biofilms, aiding infection control and the cleaning of medical devices.

Certain bacteria produce bacteriocins, killing closely related species. Nisin, a commonly used bacteriocin, acts as a food preservative.