bacterocin

In the present study, four Lactobacillus strains from the cheese were analyzed for its probiotic potential against enteropathogenic bacteria. The probiotic properties of the selected strains were also analyzed and the selected bacterial strains showed high tolerance in bile salts and organic acid. The strain L. plantarum LP049 showed maximum survival rate (92 ± 4.2% and 93.3 ± 2%) after 3 h of treatment at 0.25% (w/v) bile salts and 0.25% (w/v) organic acid concentrations. The ability of the Lactobacillus strains to adhere to human epithelial cells (HT-29 cell lines) was evaluated and L...

The objectives of this study were to detect genes for virulence and bacteriocins in addition to studying the antimicrobial susceptibility of 78 strains of E. faecalis isolated from water wells for human consumption. The virulence and bacteriocin genes of 78 E. faecalis were amplified by PCR and visualized in agarose gels. The antimicrobial susceptibility was determined through diffusion agar tests and the MIC through microdilution. It was observed that the major percentage of virulence genes in the E. faecalis strains corresponds to aggA (93...

Bacteriocins are bacteriocidal toxins released by almost all bacteria. They are thought to have a narrow range of killing, but as bacteriocin-mediated interactions have been rarely studied at biologically relevant scales, whether this narrow range of action falls mostly within or mostly between coexisting species in natural communities is an open question with important ecological and evolutionary implications. In a previous study, we systematically sampled Xenorhabdus bacteria along a hillside and found evidence for genotypic variability and bacteriocin-mediated interactions within Xenorhabdus bovienii and X...

AIMS: Study of the potential of Lactococcus lactis CECT-4434 as a biosurfactants and nisin (the only bacteriocin allowed to be used in the food industry) producer for industrial applications, exploiting the possibility of recovering separately both metabolites, taking into account that L. lactis is an interesting micro-organism with several applications in the food industry because it is recognized as GRAS. METHODS AND RESULTS: The results showed the ability of this strain to produce cell-bound biosurfactants, under controlled pH, and cell-bound biosurfactants and bacteriocins, when pH was not controlled...

The aim of this research work was to identify and characterized the bacteriocins produced by soil-associated bacteria. Bacillocin from Bacillus brevis Bb and pyocin from Pseudomonas aeruginosa Pa were found bioactive only against gram-positive bacteria tested. Maximum production of both the bacteriocins was observed at 32 degrees C in BHI medium. Production of both the bacteriocins started in the early exponential growth phase while the maximum production was observed during the stationary phase. Bacillocin Bb remained stable during 1-9 pH while pyocin Pa remained stable at pH 1-11...

BACKGROUND: Bacterocins are antimicrobial peptides produced by bacteria with a relatively narrow range of activity against closely related organisms. Subtilosin A is a bacteriocin produced by Bacillus subtilis that has activity against Listeria monocytogenes, which might indicate antimicrobial activity unusual for bacteriocins. OBJECTIVES: To examine the antimicrobial activity and factors affecting the activity of subtilosin A against a range of potentially pathogenic bacteria...

Being a human isolate and bacterocin producer with wide antimicrobial spectrum, Lactobacillus acidophilus LF221 fulfills preliminary conditions as a potential probiotic strain. To investigate the LF221 strain with respect to its persistence in complex ecosystems, viable LF221 cells were orally administered to laboratory animals (mice and piglets) and added to cheese milk. During the 10-day feeding of mice with LF221 viable cells, 0.9% of lactobacilli isolated from faeces were identical with LF221 strain. Within the piglets' feeding trial, 920 lactobacilli colonies randomly selected from faecal samples were screened for the presence of LF221-like colonies...

AIMS: The partial characterization of a bacteriocin produced by a human Lactobacillus delbrueckii isolate with probiotic potential. METHODS AND RESULTS: A bacterocin, UO004, was partially purified by cation exchange followed by a hydrophobic interaction column, biochemically characterized and the N-terminal region sequenced. Bacteriocin UO004 was found to be a hydrophobic, heat-stable polypeptide with an apparent molecular mass of 6 kDa. It was also stable and active over a wide pH range...

The synergistic and inhibitory interactions observed between Fibrobacter succinogenes A3c, Prevotella ruminicola H2b, and Ruminococcus flavefaciens B34b in the digestion of forage cellulose were studied in detail. Orchardgrass and alfalfa hays, both at two maturity stages, were used as substrates. Sequential inoculation procedures were developed whereby a second inoculation was made after the initial fermentation was killed. Total cellulose digestion from sequential addition of the organisms was then compared to values obtained in simultaneous co-culture...

Viridin B, a bacteriocin produced by Streptococcus mitis strain 42885, was shown previously to exert a bactericidal effect against a Neisseria sicca strain but only a bacteriostatic effect against a coagulase-negative staphylococcus. In the present report, this dual effect was defined further. Viridin B caused the appearance of mesosomes in both indicator strains early in the course of exposure. Whereas mesosomes were the only noticeable alterations in the staphylococcal strain at all times of exposure to bacteriocin, progressive changes occurred in the N...