African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5232

Full Length Research Paper

Partial purification and characterization of two bacteriocin-like inhibitory substances produced by bifidobacteria

Abdelmajid Zouhir1*, Ehab Kheadr2,3, Ismail Fliss2 and Jeannette Ben Hamida1
  1Unité de Protéomie Fonctionnelle et Biopréservation Alimentaire, ISSBAT, University El Manar, BP 94, Tunis cedex 1068, Tunis, Tunisia. 2Dairy Research Center STELA, Nutraceuticals and Functional Foods Institute (INAF), Laval University, Quebec, PQ, Canada, G1K 7P4, Canada. 3Department of Dairy Science and Technology, Faculty of Agriculture, University of Alexandria, Alexandria, Egypt
Email: [email protected]

  •  Published: 18 February 2011

Abstract

 

Bifidobacterium spp. RBL 68 and RBL 85 isolated from newborn faeces were found to produce two bacteriocin-like inhibitory substances (BLIS) with inhibitory activities against a wide range of Gram- positive and Gram-negative bacteria. The production of these BLIS began in late exponential phase of growth and reached a maximum activity during and after the stationary phase. An activity level of 33 and 15 AU/ml at the end of the exponential phase that is (12 h) and maximum activity (65 and 35 AU/ml) at the beginning of the stationary phase that is (24 and 36 h) were recorded in MRS broth at 37°C for RBL 68 and RBL 85, respectively. The two BLIS, produced by RBL 68 and RBL 85, were partially purified by a three-step purification protocol resulting in a specific activity of 2.66 x 10and 7.68 x 103 AU/mg and purification fold of 122.8 and 95, respectively. Complete inactivation of the two BLIS activities were observed after treatment with proteolytic enzymes, including chymotrypsin, pronase E and proteinase K. These proteinaceous compounds were active against food-borne diseases and food spoilage pathogens such as Listeria monocytogenes, which make them potentially useful as antimicrobial agents in foods.

 

Key words: Bifidobacterium spp., bacteriocin-like inhibitory substance, bacteriocin-like inhibitory substances activity.