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Partial characterization of bacteriocins produced by environmental strain Enterococcus faecium EK13
M Mareková1, A Lauková, L DeVuyst
1Institute of Medical Chemistry and Biochemistry, Medical Faculty, Kosice, Slovakia. mmarek@central.medic.upjs.sk
Journal of Applied Microbiology
|February 18, 2003
Summary
An environmental Enterococcus faecium strain EK13 from cattle dung produces two bacteriocins, enterocin A and P. These bacteriocins show broad-spectrum antimicrobial activity and have potential for biotechnological applications.
Area of Science:
- Microbiology
- Biochemistry
- Food Science
Background:
- Bacteriocins are ribosomally synthesized antimicrobial peptides with significant potential in food preservation and therapeutics.
- Enterococcus faecium is known to produce various bacteriocins, but novel producers from environmental sources are of great interest.
- Characterization of bacteriocins from unique environmental niches can reveal new antimicrobial agents.
Purpose of the Study:
- To partially characterize bacteriocins produced by an environmental isolate, Enterococcus faecium EK13, obtained from cattle dung water.
- To identify the specific bacteriocins produced by E. faecium EK13 and assess their properties.
- To explore the potential of E. faecium EK13 for biotechnological applications, such as waste treatment.
Main Methods:
- Partial purification of bacteriocins using ammonium sulphate precipitation, SP-Sepharose chromatography, and reverse-phase chromatography.
- N-terminal amino acid sequencing and PCR to identify the bacteriocins.
- Determination of bacteriocin stability, optimal production conditions (pH, temperature), and fermentation kinetics.
- Antimicrobial activity assays against various indicator strains, including Listeria innocua.
Main Results:
- Enterocin A (4.83 kDa) and enterocin P were identified as the bacteriocins produced by E. faecium EK13.
- Bacteriocins exhibited heat stability and were stable at 4 and -20°C.
- Optimal production occurred at pH 5.0-6.5 and temperatures of 30-37°C during the logarithmic growth phase.
- Highest activity reached 51,200 AU/ml against Listeria innocua LMG 13568.
Conclusions:
- Enterococcus faecium EK13 is a novel producer of enterocin A and enterocin P.
- These bacteriocins possess broad-spectrum inhibitory activity against Gram-positive bacteria, including pathogenic genera.
- The strain holds potential for utilization in biotechnological processes, including waste treatment.