Isolation and characterization of enterocin EJ97, a bacteriocin produced by Enterococcus faecalis EJ97

Area of Science:

• Microbiology
• Bacteriology
• Biochemistry

Background:

• Enterococcus faecalis is a common bacterium found in various environments.
• Bacteriocins are ribosomally synthesized antimicrobial peptides with diverse applications.
• Novel bacteriocins are sought for their potential antimicrobial properties.

Purpose of the Study:

• To isolate and characterize a bacteriocin from Enterococcus faecalis EJ97.
• To determine the antimicrobial spectrum and properties of the novel bacteriocin, enterocin EJ97.
• To investigate the effect of enterocin EJ97 on target bacteria.

Main Methods:

• Isolation of bacteriocinogenic Enterococcus faecalis EJ97 from municipal wastewater.
• Purification and molecular mass determination of enterocin EJ97.
• Amino acid sequencing of the N-terminal residues.
• Antimicrobial activity assays against various Gram-positive bacteria.
• Determination of bacteriocin stability and sensitivity to enzymes.
• Assessment of bactericidal and bacteriolytic effects.

Main Results:

• Enterococcus faecalis EJ97 produces a cationic bacteriocin, enterocin EJ97 (5,340 Da).
• Enterocin EJ97 is heat-stable under mild conditions, sensitive to proteases, and has a unique N-terminal sequence.
• The bacteriocin exhibits broad-spectrum activity against Enterococci, Bacillus, Listeria, and Staphylococcus aureus.
• The producer strain EJ97 is resistant to enterocin EJ97.
• Enterocin EJ97 demonstrates concentration-dependent bactericidal and bacteriolytic effects on E. faecalis S-47.

Conclusions:

• Enterocin EJ97 is a novel bacteriocin with significant antimicrobial activity against Gram-positive bacteria.
• Its unique properties and effectiveness suggest potential applications in food preservation and as a therapeutic agent.
• Further research into enterocin EJ97 could lead to new strategies for combating bacterial infections and spoilage.