How do microorganisms use antibiotic substances to compete with other organisms?

Microorganisms, such as bacteria and fungi, use antibiotic substances as a biological strategy to control the growth of competing organisms in complex environments like soil. This interaction is a form of amensalism known as antibiosis, where one organism secretes a chemical that damages or kills its competitors while remaining unaffected itself.12

These substances function through various biochemical mechanisms to disrupt essential life processes in competing cells:

• Cell Wall Inhibition: Some antibiotics, such as $\beta$-lactams, interfere with the synthesis of the bacterial cell wall, leading to structural failure and cell death.3
• Protein Synthesis Interference: Agents like aminoglycosides and erythromycin bind to bacterial components to prevent the production of proteins necessary for survival.3
• Membrane Disruption: Substances like polymyxin B bind to phospholipids in the cell membrane, causing essential molecules to leak out of the cell.3
• Metabolic Inhibition: Compounds like sulfonamides act as competitive inhibitors, blocking the synthesis of folic acid and preventing the organism from producing nucleic acids.3

By deploying these chemical defenses, microorganisms effectively reduce competition for resources in their immediate surroundings.14