Purification and characterization of a bacteriocin produced by Lactobacillus acidophilus IBB 801

Abstract

M. ZAMFIR, R. CALLEWAERT, P.C. CORNEA, L. SAVU, I. VATAFU and L. DE VUYST.1999.Lactobacillus acidophilus IBB 801 produces a small bacteriocin, designated acidophilin 801, with an estimated molecular mass of less than 6·5 kDa. It displays a narrow inhibitory spectrum (only related lactobacilli but including the Gram‐negative pathogenic bacteria Escherichia coli Row and Salmonella panama 1467) with a bactericidal activity. The antimicrobial activity of cell‐free culture supernatant fluid was insensitive to catalase but sensitive to proteolytic enzymes such as trypsin, proteinase K and pronase, heat‐stable (30 min at 121 °C), and maintained in a wide pH range. The proteinaceous compound was isolated from cell‐free culture supernatant fluid and purified. Crude bacteriocin was isolated as a floating pellicle after ammonium sulphate precipitation (40% saturation) and partially purified by extraction/precipitation with chloroform/methanol (2/1, v/v). Further purification to homogeneity was performed by reversed phase Fast Performance Liquid Chromatography. The amino acid composition was determined. Amino acid sequencing revealed that the N‐terminal end was blocked.

Probiotic Bacterium Prevents Cytokine-induced Apoptosis in Intestinal Epithelial Cells

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Anti-Infective Activities of Lactobacillus Strains in the Human Intestinal Microbiota: from Probiotics to Gastrointestinal Anti-Infectious Biotherapeutic Agents

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