Effect on bone anabolic markers of daily cheese intake with and without vitamin K: a randomised clinical trial.

Background: Daily intake of 57 g Jarlsberg cheese has been shown to increase the total serum osteocalcin (tOC). Is this a general cheese effect or specific for Jarlsberg containing vitamin K and 1,4-dihydroxy-2naphtoic acid (DHNA)?

Methods: 66 healthy female volunteers (HV) were recruited. By skewed randomisation (3:2), 41 HV were allocated to daily intake of 57 g Jarlsberg (J-group) and 25-50 g Camembert (C-group) in 6 weeks.

Genome-assisted Identification, Purification, and Characterization of Bacteriocins.

Bacteriocins are antimicrobial peptides with activity against antibiotic resistant bacterial pathogens. Here, we describe a set of methods aimed at purifying, identifying, and characterizing new bacteriocins. The purification consists of ammonium sulphate precipitation, cation-exchange chromatography, and reversed-phase chromatography.

Purification and characterization of bacteriocins-like inhibitory substances from food isolated Enterococcus faecalis OS13 with activity against nosocomial enterococci.

Nosocomial infections caused by enterococci are an ongoing global threat. Thus, finding therapeutic agents for the treatment of such infections are crucial. Some Enterococcus faecalis strains are able to produce antimicrobial peptides called bacteriocins.

The CWPS Rubik's cube: Linking diversity of cell wall polysaccharide structures with the encoded biosynthetic machinery of selected Lactococcus lactis strains.

The biosynthetic machinery for cell wall polysaccharide (CWPS) production in lactococci is encoded by a large gene cluster, designated cwps. This locus displays considerable variation among lactococcal genomes, previously prompting a classification into three distinct genotypes (A-C). In the present study, the cwps loci of 107 lactococcal strains were compared, revealing the presence of a fourth cwps genotype (type D).

Engineering for Increased Vitamin K2 Production.

Cheese produced with is the main source of vitamin K2 in the Western diet. Subclinical vitamin K2 deficiency is common, calling for foods with enhanced vitamin K2 content. In this study we describe analyses of vitamin K2 (menaquinone) production in the lactic acid bacterium ssp.

Unprecedented Diversity of Lactococcal Group 936 Bacteriophages Revealed by Amplicon Sequencing of the Portal Protein Gene.

is one of the most important bacteria in dairy fermentations, being used in the production of cheese and buttermilk. The processes are vulnerable to phage attacks, and undefined mixtures of lactococcal strains are often used to reduce the risk of bacteriophage caused fermentation failure. Other preventive measures include culture rotation to prevent phage build-up and phage monitoring.

Lactococcus lactis Diversity in Undefined Mixed Dairy Starter Cultures as Revealed by Comparative Genome Analyses and Targeted Amplicon Sequencing of .

Undefined mesophilic mixed (DL) starter cultures are used in the production of continental cheeses and contain unknown strain mixtures of and leuconostocs. The choice of starter culture affects the taste, aroma, and quality of the final product. To gain insight into the diversity of strains in starter cultures, we whole-genome sequenced 95 isolates from three different starter cultures.

Synergistic Antimicrobial Activity Between the Broad Spectrum Bacteriocin Garvicin KS and Nisin, Farnesol and Polymyxin B Against Gram-Positive and Gram-Negative Bacteria.

The increasing emergence of antibiotics resistance is of global concern. Finding novel antimicrobial agents and strategies based on synergistic combinations are essential to combat resistant bacteria. We evaluated the activity of garvicin KS, a new bacteriocin produced by Lactococcus garvieae.

Genomic Characterization of Dairy Associated Species and Diversity of Leuconostocs in Undefined Mixed Mesophilic Starter Cultures.

Undefined mesophilic mixed (DL-type) starter cultures are composed of predominantly subspecies and 1-10% spp. The composition of the population in the starter culture ultimately affects the characteristics and the quality of the final product. The scientific basis for the taxonomy of dairy relevant leuconostocs can be traced back 50 years, and no documentation on the genomic diversity of leuconostocs in starter cultures exists.

Novel Group of Leaderless Multipeptide Bacteriocins from Gram-Positive Bacteria.

Unlabelled: From raw milk we found 10 Lactococcus garvieae isolates that produce a new broad-spectrum bacteriocin. Though the isolates were obtained from different farms, they turned out to possess identical inhibitory spectra, fermentation profiles of sugars, and repetitive sequence-based PCR (rep-PCR) DNA patterns, indicating that they produce the same bacteriocin. One of the isolates (L.

Draft Genome Sequence of the Bacteriocin-Producing Strain Enterococcus faecium M3K31, Isolated from Griffon Vultures (Gyps fulvus subsp. fulvus).

Enterococcus faeciumM3K31 is a bacteriocinogenic lactic acid bacterium (LAB) isolated from griffon vulture (Gyps fulvussubsp.fulvus) feces. The draft genome sequence of this strain provides genetic data that support its biotechnological potential.

EF0176 and EF0177 from Enterococcus faecalis V583 are substrate-binding lipoproteins involved in ABC transporter mediated ribonucleoside uptake.

One of the ABC transporter systems in Enterococcus faecalis V583 is encoded by the ef0176-ef0180 gene cluster, which differs from orthologous operons in related bacteria in that it contains two genes putatively encoding substrate-binding proteins (SBPs). These SBPs, EF0176 and EF0177, have previously been identified on the surface of E. faecalis.

Using a genome-scale metabolic model of Enterococcus faecalis V583 to assess amino acid uptake and its impact on central metabolism.

Increasing antibiotic resistance in pathogenic bacteria necessitates the development of new medication strategies. Interfering with the metabolic network of the pathogen can provide novel drug targets but simultaneously requires a deeper and more detailed organism-specific understanding of the metabolism, which is often surprisingly sparse. In light of this, we reconstructed a genome-scale metabolic model of the pathogen Enterococcus faecalis V583.

Enterococcus faecalis grows on ascorbic acid.

We show that Enterococcus faecalis can utilize ascorbate for fermentative growth. In chemically defined media, growth yield was limited by the supply of amino acids, and the cells showed a much higher demand for amino acids than when they were grown on glucose.

Novel Podoviridae family bacteriophage infecting Weissella cibaria isolated from Kimchi.

The first complete genome sequence of a phage infecting Weissella cibaria (Weissella kimchii) is presented. The bacteriophage YS61 was isolated from kimchi, a Korean fermented vegetable dish. Bacteriophages are recognized as a serious problem in industrial fermentations; however, YS61 differed from many virulent phages associated with food fermentations since it was difficult to propagate and was very susceptible to resistance development.

Characterization of a Leuconostoc bacteriophage infecting flavor producers of cheese starter cultures.

Dairy siphovirus φLmd1, which infects starter culture isolate Leuconostoc mesenteroides subsp. dextranicum A1, showed resistance to pasteurization and was able to grow on 3 of the 4 commercial starter cultures tested. Its 26,201-bp genome was similar to that of Leuconostoc phage of vegetable origin but not to those of dairy phages infecting Lactococcus.

Target recognition, resistance, immunity and genome mining of class II bacteriocins from Gram-positive bacteria.

Due to their very potent antimicrobial activity against diverse food-spoiling bacteria and pathogens and their favourable biochemical properties, peptide bacteriocins from Gram-positive bacteria have long been considered promising for applications in food preservation or medical treatment. To take advantage of bacteriocins in different applications, it is crucial to have detailed knowledge on the molecular mechanisms by which these peptides recognize and kill target cells, how producer cells protect themselves from their own bacteriocin (self-immunity) and how target cells may develop resistance. In this review we discuss some important recent progress in these areas for the non-lantibiotic (class II) bacteriocins.

Transcriptome, proteome, and metabolite analyses of a lactate dehydrogenase-negative mutant of Enterococcus faecalis V583.

A constructed lactate dehydrogenase (LDH)-negative mutant of Enterococcus faecalis V583 grows at the same rate as the wild type but ferments glucose to ethanol, formate, and acetoin. Microarray analysis showed that LDH deficiency had profound transcriptional effects: 43 genes in the mutant were found to be upregulated, and 45 were found to be downregulated. Most of the upregulated genes encode enzymes of energy metabolism or transport.

Wide-Inhibitory Spectra Bacteriocins Produced by Lactobacillus gasseri K7.

The aim of our study was to determine the genetic characterization and classification of Lb. gasseri K7 bacteriocins, comparison with bacteriocins of the Lb. gasseri LF221 strain and other related strains.

The unconventional antimicrobial peptides of the classical propionibacteria.

The classical propionibacteria produce genetically unique antimicrobial peptides, whose biological activities are without equivalents, and to which there are no homologous sequences in public databases. In this review, we summarize the genetics, biochemistry, biosynthesis, and biological activities of three extensively studied antimicrobial peptides from propionibacteria. The propionicin T1 peptide constitutes a bona fide example of an unmodified general secretory pathway (sec)-dependent bacteriocin, which is bactericidal towards all tested species of propionibacteria except Propionibacterium freudenreichii.

Specific degradation of the mucus adhesion-promoting protein (MapA) of Lactobacillus reuteri to an antimicrobial peptide.

The intestinal flora of mammals contains lactic acid bacteria (LAB) that may provide positive health effects for the host. Such bacteria are referred to as probiotic bacteria. From a pig, we have isolated a Lactobacillus reuteri strain that produces an antimicrobial peptide (AMP).

Class IIa bacteriocin resistance in Enterococcus faecalis V583: the mannose PTS operon mediates global transcriptional responses.

Background: The class IIa bacteriocin, pediocin PA-1, has clear potential as food preservative and in the medical field to be used against Gram negative pathogen species as Enterococcus faecalis and Listeria monocytogenes. Resistance towards class IIa bacteriocins appear in laboratory and characterization of these phenotypes is important for their application. To gain insight into bacteriocin resistance we studied mutants of E.

Nukacin 3299, a lantibiotic produced by Staphylococcus simulans 3299 identical to nukacin ISK-1.

Nukacin 3299 (formerly designated simulancin 3299), produced by a Staphylococcus simulans strain involved in bovine mastitis in Brazil, is the first peptide bacteriocin described in this staphylococcal species. With the intent to elucidate some aspects of its biology, nukacin 3299 was purified and characterized. The mass of the purified bacteriocin was shown to be 2957.

Molecular and genetic characterization of a novel bacteriocin locus in Enterococcus avium isolates from infants.

Enterococci are among the most common human intestinal lactic acid bacteria, and they are known to produce bacteriocins. In this study, fecal enterococci were isolated from infants and screened for bacteriocin production. Bacteriocin-producing Enterococcus avium isolates were obtained, and a new pediocin-like bacteriocin was purified and characterized.