Bacteriocin production by Lactobacillus salivarius CRL1384 with anti-Listeria and anti-Salmonella effects

AUDISIO M. C; APELLA M. C.

Roma

Congreso; 2nd Probiotics, Prebiotics and New Foods; 2003

Universita Urbaniana

Lactobacilli are important part of healthy intestinal microflora of different hosts because through many mechanisms they could inhibit pathogenic or spoilage bacteria. In particular, Lactobacillus salivarius strains have been employed in probiotic supplements or competitive exclusion cultures not only for human but also for chickens principally because of their high lactic acid production. However, little is known about their bacteriocin synthesis ability. Few articles report bacteriocin production by this micro-organism and no one of them have avian origin. Lactobacillus salivarius CRL1384 was isolated from the crop of a free-range chicken and screened for the production of antimicrobial activity, using a target panel of spoilage organisms and pathogens. This strain produces a broad spectrum bacteriocin which inhibits the growth of Listeria monocytogenes, Enterococcus hirae and some gram-negative pathogens such as Salmonella. This new bacteriocin is sensitive to trypsin, proteinase K, pronase E, alpha-chymotripsin, papain and pepsin; it is not sensitive to lipase and alpha-amylase partially reduces its activity. Besides, it is heat-stable (121 degrees C for 15 min) and through an SDS-PAGE assay, the partly purified activity migrates as a peptide of 6 kDa. This bacteriocin can be synthesised by Lact. salivarius not only in the presence of glucose but also in the presence of sucrose or maltose, both sugars together or more complex carbohydrate molecules such as fructooligosaccharides (FOS). Genetic analyses revealed not plasmid, so we infer that the information for this bacteriocin production is encoded at chromosomal level. This result is important because that means an stable property. Lactobacilli are important part of healthy intestinal microflora of different hosts because through many mechanisms they could inhibit pathogenic or spoilage bacteria. In particular, Lactobacillus salivarius strains have been employed in probiotic supplements or competitive exclusion cultures not only for human but also for chickens principally because of their high lactic acid production. However, little is known about their bacteriocin synthesis ability. Few articles report bacteriocin production by this micro-organism and no one of them have avian origin. Lactobacillus salivarius CRL1384 was isolated from the crop of a free-range chicken and screened for the production of antimicrobial activity, using a target panel of spoilage organisms and pathogens. This strain produces a broad spectrum bacteriocin which inhibits the growth of Listeria monocytogenes, Enterococcus hirae and some gram-negative pathogens such as Salmonella. This new bacteriocin is sensitive to trypsin, proteinase K, pronase E, alpha-chymotripsin, papain and pepsin; it is not sensitive to lipase and alpha-amylase partially reduces its activity. Besides, it is heat-stable (121 degrees C for 15 min) and through an SDS-PAGE assay, the partly purified activity migrates as a peptide of 6 kDa. This bacteriocin can be synthesised by Lact. salivarius not only in the presence of glucose but also in the presence of sucrose or maltose, both sugars together or more complex carbohydrate molecules such as fructooligosaccharides (FOS). Genetic analyses revealed not plasmid, so we infer that the information for this bacteriocin production is encoded at chromosomal level. This result is important because that means an stable property. Lactobacilli are important part of healthy intestinal microflora of different hosts because through many mechanisms they could inhibit pathogenic or spoilage bacteria. In particular, Lactobacillus salivarius strains have been employed in probiotic supplements or competitive exclusion cultures not only for human but also for chickens principally because of their high lactic acid production. However, little is known about their bacteriocin synthesis ability. Few articles report bacteriocin production by this micro-organism and no one of them have avian origin. Lactobacillus salivarius CRL1384 was isolated from the crop of a free-range chicken and screened for the production of antimicrobial activity, using a target panel of spoilage organisms and pathogens. This strain produces a broad spectrum bacteriocin which inhibits the growth of Listeria monocytogenes, Enterococcus hirae and some gram-negative pathogens such as Salmonella. This new bacteriocin is sensitive to trypsin, proteinase K, pronase E, alpha-chymotripsin, papain and pepsin; it is not sensitive to lipase and alpha-amylase partially reduces its activity. Besides, it is heat-stable (121 degrees C for 15 min) and through an SDS-PAGE assay, the partly purified activity migrates as a peptide of 6 kDa. This bacteriocin can be synthesised by Lact. salivarius not only in the presence of glucose but also in the presence of sucrose or maltose, both sugars together or more complex carbohydrate molecules such as fructooligosaccharides (FOS). Genetic analyses revealed not plasmid, so we infer that the information for this bacteriocin production is encoded at chromosomal level. This result is important because that means an stable property.