African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12278

Full Length Research Paper

Bacteriocinogenic potential and genotypic characterization of three Enterococcus faecium isolates from Algerian raw milk and traditional butter

Louiza Lazreg*
  • Louiza Lazreg*
  • Department of Biotechnology, Faculty of Nature and Life Sciences, University of Sciences and Technology, Mohamed Boudiaf Oran, BP 1505 El Mnaouar, 31000, Algeria.
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Fatiha Dalache
  • Fatiha Dalache
  • Department of Biology, University of Mostaganem, 27000, Algeria.
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Halima Zadi-Karam
  • Halima Zadi-Karam
  • Laboratory of Biology of Microorganisms and Biotechnology, University of Oran 1 Ahmed Ben Bella, Algeria.
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Nour-Eddine Karam
  • Nour-Eddine Karam
  • Laboratory of Biology of Microorganisms and Biotechnology, University of Oran 1 Ahmed Ben Bella, Algeria.
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  •  Received: 22 February 2015
  •  Accepted: 06 August 2015
  •  Published: 12 August 2015

Abstract

The detection of bacteriocinogenic potential of Enterococcus sp. isolates from Algerian raw milk coded LO4 and LO12 and from traditional butter coded BRO2 was carried on M17 buffered medium. PCR amplification of Enterococcus sp. DNA using specific enterococcal primers gave 733 bp fragments. The phylogenetic analysis using the neighbour joining method further supported the identification of the three strains as Enterococcus faecium. These bacteria were bacteriocinogenic against Pseudomonas sp, Proteus mirabilis and E. faecium. Lyophilisate extracts were tested for sensitivity to enzymes, heating and effect of pH. Complete inactivation in bacteriocinogenic activity was observed after treatment with proteolytic enzymes. The antibacterial activity from E faecium LO12 was stable (1280 AU/ml) for range pH 2 to 12. Maximal activity from BRO2 strain was at pH 7 (20480 AU/ml) and from LO4 strain was at pH 7 and 6 (2560 AU/ml). Antibacterial activities of E. faecium BRO2 (5120 AU/ml) and E. faecium LO12 (640 AU/ml) remained stable at 60°C for 30 min. The antibacterial activity of .E faecium LO4 was stable at 100°C for 30 min (5120 AU/ml).

 

Key words: Butter, milk, Enterococcus faecium, antibacterial activity, bacteriocinogenic.