What is the Difference Between Bacteriocins and Antibiotics

The main difference between bacteriocins and antibiotics is that bacteriocins are synthesized on the bacterial ribosomal surfaces, whereas antibiotics are synthesized inside bacteria as secondary metabolites.

Bacteriocins and antibiotics are two types of substances that act against similar or other bacteria. Generally, both can act as antimicrobials.

Key Areas Covered

1. What are Bacteriocins
– Definition, Features, Function
2. What are Antibiotics
– Definition, Features, Function
3. Similarities – Bacteriocins and Antibiotics
– Outline of Common Features
4. Difference Between Bacteriocins and Antibiotics
– Comparison of Key Differences

Key Terms                                                                                                                  

Antibiotics, Bacteriocins

What are Bacteriocins

Bacteriocins are proteinaceous toxins produced by some bacteria in order to inhibit the growth of similar or closely-related bacteria. They are structurally, functionally, and ecologically diverse. However, the applications of bacteriocins are like narrow-spectrum antibiotics. Therefore, bacteriocins are antimicrobials. Hydrogen peroxide, fatty acids, organic acids, ethanol, lytic enzymes, bacteriophages, and antibiotics are the other types of antimicrobial agents. Additionally, bacteriocins were first discovered by André Gratia in 1925.

Figure 1: Lactococcin

Furthermore, bacteriocins have several types according to their method of production, molecular weight and chemistry, genetics, and mechanism of killing. Generally, there are three methods of producing bacteriocins. They include ribosomal production, post-ribosomal production, and non-ribosomal production. According to the molecular weight and chemistry, there can be bacteriocins like peptides and large proteins, with/without sugar moiety, and containing atypical amino acids such as lanthionine. In addition, genetically, bacteriocins can have a chromosomal, large, or small plasmid origin. Moreover, bacteriocins can have nuclease activity, pore-forming, and peptidoglycan production inhibition activity according to the method of killing.    

What are Antibiotics

Antibiotics are a type of antimicrobial substance that acts against several bacteria. They are secondary metabolites. However, antibiotics are the most important type of antimicrobial agents, and therefore, they are important as medicines fighting against bacterial infections. They are significant in treating and preventing bacterial infections. Antibiotics can either kill or inhibit the growth of bacteria. But they are not active against other microbes, including viruses and fungi.

Figure 2: Penicillin

Moreover, antibiotics are chemical agents produced by bacteria, detrimental to other bacteria. The main importance of antibiotics is that they are produced by soil bacteria against the competing bacteria living in the soil. However, the first antibiotic found was penicillin, discovered by Scottish bacteriologist Alexander Fleming in 1928.

Similarities Between Bacteriocins and Antibiotics

• Bacteriocins and antibiotics are two types of antimicrobial agents that act against similar or related bacteria.
• They serve as a part of immune reactions and defense mechanisms in bacteria.
• Therefore, they enhance the ability to compete for space and resources.
• Both are produced inside bacteria.
• They are good evidence of their microbial antagonism.

Difference Between Bacteriocins and Antibiotics

Definition

Bacteriocins refer to proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s), while antibiotics refer to a medicine (such as penicillin or its derivatives) that inhibits the growth of or destroys microorganisms.

Application

Bacteriocins are important in the food industry, while antibiotics are important in clinical applications.

Synthesis

Bacteriocins are synthesized on the bacterial ribosomal surfaces, while antibiotics are synthesized inside bacteria as secondary metabolites.

Activity

While bacteriocins are a narrow spectrum, antibiotics are a varying spectrum.

Host Cell Immunity

Host cell immunity works against bacteriocins, while host cell immunity does not work against antibiotics.

Mechanism of Target Cell Resistance

In bacteriocins, the target cell undergoes adaptations, affecting the cell membrane composition, while in antibiotics, the target cell uses genetically transferable determinants, affecting different sites depending on the mode of action.

Interaction Requirements

Bacteriocins undergo docking molecules, while antibiotics use specific targets.

Mode of Action

Bacteriocins undergo pore formation or cell wall biosynthesis, while antibiotics undergo cell membrane or intracellular targets.

Toxicity

The toxicity of bacteriocins is unknown, while antibiotics are toxic.

Conclusion                                                      

In brief, bacteriocins and antibiotics are two types of antimicrobial agents. Their function is to act against similar or related bacteria. Generally, bacteriocins are important in the food industry. Target cells undergo adaptations in cell membrane composition against bacteriocins. However, bacteriocins form pores in the cell wall to kill the bacteria. In comparison, antibiotics are secondary metabolites that are toxic to other bacteria. Therefore, other bacteria use genetically transferable determinants to act against antibiotics. However, the main difference between bacteriocins and antibiotics is their effect on other bacteria.                               

References:                

1. “Bacteriocins: Properties and potential use as antimicrobials.” Wiley Online Library.
2. “Antibiotic. “Encyclopædia Britannica. 

Image Courtesy:

1. “Lactococcin 972 PDB=2LGN” By Turner, D.L., Lamosa, P., Martinez, B., Synpath – Own work (CC0) via Commons Wikimedia
2. “Penicillin core” By Yikrazuul – Own Work (Public Domain) via Commons Wikimedia