Most inhibitory substances produced by lactic acid bacteria are safe and effective natural inhibitors of pathogenic and food spoilage bacteria in various foods. In this study, bacteriocin nisin producing Lactococcus lactis was isolated from fermented milk and cheese. The test isolate was grown in MRS medium under optimized conditions. Bacteriocin activity of the test isolate was determined by a...

Like any form of cooperative behavior, quorum sensing (QS) in bacteria is potentially vulnerable to cheating, the occurrence of individuals that contribute less but still profit from the benefits provided by others. In this paper, we explore the evolutionary stability of QS as a regulatory mechanism of antibiotics production in a spatially structured population, using cellular automaton (CA) mo...

A dramatic increase in bacterial resistance towards currently available antibiotics has raised worldwide concerns for public health. Therefore, antimicrobial peptides (AMPs) have emerged as a promisingly new group of therapeutic agents for managing infectious diseases. The present investigation focusses on the isolation and purification of a novel bacteriocin from an indigenous sample of cow mi...

A correlation between the presence of 5.6-kilobase plasmids and bacteriocin activity was found in human-derived strains of Streptococcus mutans. Compared with bacteriocin activity of randomly selected clinical isolates of plasmid-negative strains, bacteriocin activity of plasmid-positive strains significantly inhibited not only two laboratory strains of S. mutans, OMZ176 and AHT (P less than 0....

The bacteriocin produced by Pediococcus acidilactici PAC 1.0, previously designated PA-1 bacteriocin, was found to be inhibitory and bactericidal for Listeria monocytogenes. A dried powder prepared from PAC 1.0 culture supernatant fortified with 10% milk powder was found to contain bacteriocin activity. An MIC against L. monocytogenes and lytic effects in broth cultures were determined. Inhibit...

Aims: The aim of the present study is to investigate the effect of bacteriocin from Pseudomonas putida FStm2 on biofilm-forming bacteria isolated from urinary catheter. Methodology and results: In this study, 25 bacteria isolates were successfully isolated from urinary catheter. Sixteen of the isolates were urease positive. Results of crystal violet test showed that 8 isolates were active biofi...

Microbial production of antimicrobials as biopreservatives is the major area of focus nowadays due to increased interest of consumers towards natural and safe preservation of ready to eat food products. The agro-industrial byproduct based medium and optimized process conditions can contribute in economical production of bacteriocins. Keeping this in view, the present investigation was carried o...

This work describes the purification and characterization of propionicin F, the first bacteriocin isolated from Propionibacterium freudenreichii. The bacteriocin has a bactericidal activity and is only active against strains of P. freudenreichii. Propionicin F appears to be formed through a processing pathway new to bacteriocins. The mass of the purified bacteriocin was determined by mass spect...

The lactic acid bacterium Lactococcus lactis IFPL105 secretes a broad spectrum bacteriocin produced from the 46 kb plasmid pBAC105. The bacteriocin was purified to homogeneity by ionic and hydrophobic exchange and reverse-phase chromatography. Bacteriocin activity required the complementary action of two distinct peptides (alpha and beta) with average molecular masses of 3322 and 2848 Da, respe...

Pathogens resistant to most conventional antibiotics warrant the need to discover novel antimicrobials and develop innovative strategies to combat them. The aim of this study was to assess the in vitro antimicrobial activities of bacteriocins in culture supernatants of vaginal Lactobacilli alone or in combination with conventional antibiotics against Salmonella typhimurium, Pseudomonas aerugino...