Publications by authors named "Hillier A"

Current knowledge of the genomes of the lactic acid bacteria, Lactococcus lactis and Streptococcus thermophilus, and members of the genera Lactobacillus, Leuconostoc, Pediococcus and Carnobacterium, is reviewed. The genomes contain a chromosome within the size range of 1.8 to 3.

View Article and Find Full Text PDF

A novel peptide bacteriocin produced by the lactic acid bacterium Carnobacterium piscicola JG126 isolated from spoiled ham was purified and characterized. This bacteriocin, designated piscicolin 126, inhibited the growth of several gram-positive bacteria, especially the food-borne pathogen Listeria monocytogenes, but had no effect on the growth of a number of yeasts and gram-negative bacteria. Bactericidal activity was not destroyed by exposure to elevated temperatures at low pH values; however, bactericidal activity was lost at high pH values, especially when high pH values were combined with an elevated temperature.

View Article and Find Full Text PDF

Spontaneous deletion mutants of the temperate lactococcal bacteriophage BK5-T were obtained when the phage was grown vegetatively on the indicator strain Lactococcus lactis subsp. cremoris H2. One deletion mutant was unable to form stable lysogens, and analysis of this mutant led to the identification of the BK5-T attP site and the integrase gene (int).

View Article and Find Full Text PDF

Bacteriophage BK5-T is a small isometric-headed temperate phage that infects Lactococcus lactis subsp. cremoris. Northern (RNA) analysis of mRNA produced by lysogenic strains containing BK5-T prophage revealed four major BK5-T transcripts that are 0.

View Article and Find Full Text PDF

The Lactococcus lactis temperate bacteriophage BK5-T is a type phage in the lactococcal phage classification (A. W. Jarvis, G.

View Article and Find Full Text PDF

Lactococcal phage abortive infection (AbiD1) determined by plasmid pIL105 is active on both prolate- and small-isometric-head phages of the C6A and 936 phage groups, respectively, which are considered two different species. The Abi phenotype was found to be encoded by a single gene, designated abiD1. The abiD1-encoded protein (351 amino acids) does not show homology with any known protein and has a deduced isoelectric point of 10.

View Article and Find Full Text PDF

The genus Lactococcus contains four species of which L. lactis is the most thoroughly studied. Its genome is A+T-rich and consists of a circular chromosome of 2.

View Article and Find Full Text PDF

In situ atomic force microscope observations were made of the adsorption of anions (1- or 2-) of the organic diacid 5-benzoyl-4-hydroxy-2-methoxybenzenesulfonic acid from aqueous solution onto the (0001) surface of hydrotalcite (HT), a layered clay. This adsorption process is believed to mimic the ion-exchange reactions that occur within the layers of HT and other layered clays. Atomic force microscope images of the (0001) surfaces of HT, acquired in aqueous solutions, reveal an ordered structure with respect to magnesium and aluminum atoms.

View Article and Find Full Text PDF

Résumé- Un chien, jeune adulte, a été présenté pour une masse sous-cutanée évoluant depuis un mois sur la partie droite du thorax et une masse ulcérée sous-cutanée sur la cuisse droite. L'examen histo-pathologique a révélé une inflammation pyogranulomateuse du derme et du tissu sous-cutané avec de larges hyphes fongiques. De nouvelles lésions sont apparues.

View Article and Find Full Text PDF

Bacteriophage sk1 is a small isometric-headed lytic phage that infects Lactococcus lactis. The phage has a linear double-stranded DNA genome of 28 kbp, with cohesive ends. RNA was prepared from phage-infected L.

View Article and Find Full Text PDF

In situ atomic force microscopy reveals the morphology, surface topography, and growth and dissolution characteristics of microscopic single crystals of the low-dimensional organic conductor (tetrathiafulvalene)Br(0.76)' which are grown by electrocrystallization on a highly oriented pyrolytic graphite electrode in an atomic force microscope liquid cell. The growth modes and the distribution and orientation of topographic features on specific crystal faces, whose identity was determined by "atomic force microscope goniometry," can be correlated with the strength and direction of anisotropic solid-state intermolecular bonding.

View Article and Find Full Text PDF

The location, structure and nature of the cos site of the Lactococcus lactis bacteriophage sk1 was determined using a Taq DNA polymerase runoff sequencing technique. The cos site contains a single-stranded 3' overhang of 11 nucleotides. The region surrounding cos contains several features which may be involved in the binding and catalytic action of a phage terminase.

View Article and Find Full Text PDF

The discovery of a novel multicistronic operon that encodes phosphofructokinase, pyruvate kinase, and lactate dehydrogenase in the lactic acid bacterium Lactococcus lactis is reported. The three genes in the operon, designated pfk, pyk, and ldh, contain 340, 502, and 325 codons, respectively. The intergenic distances are 87 bp between pfk and pyk and 117 bp between pyk and ldh.

View Article and Find Full Text PDF

Pulsed-field agarose gel electrophoresis of SmaI digests of genomic DNA was used to examine lactose plasmid copy number and stability in Lactococcus lactis. In L. lactis strain DRC1, the plasmid was found to exist as a single-copy plasmid.

View Article and Find Full Text PDF

A gene (designated ldh) that encodes fructose-1,6-bisphosphate-activated L-(+)-lactate dehydrogenase was cloned from Lactococcus lactis subsp. lactis. Plasmids containing ldh conferred fructose-1,6-bisphosphate-activated L-(+)-lactate dehydrogenase activity on Escherichia coli cells.

View Article and Find Full Text PDF

Bacteriophage c6A is a lytic phage that infects strains of Lactococcus lactis. Infection of L. lactis strain C6 resulted in inhibition of culture growth within 10 min, mature intracellular phage particles appeared after 17.

View Article and Find Full Text PDF

Arbitrarily primed polymerase chain reaction, with incorporation of either radioactive or fluorescent labels, was used as a rapid and sensitive method for obtaining genomic fingerprints of strains of Lactococcus lactis. Closely related strains produced almost identical fingerprints. Fingerprints of other strains showed only some similarities.

View Article and Find Full Text PDF

Nisin-producing transconjugants were generated by mating nisin-producing strains of Lactococcus lactis subsp. lactis with derivatives of L. lactis subsp.

View Article and Find Full Text PDF

A physical map of the chromosome of Lactococcus lactis subsp. lactis DL11 was constructed by using the contour-clamped homogeneous electric field mode of pulsed-field gel electrophoresis in one- and two-dimensional separations to analyze restriction digests of high-molecular-weight genomic DNA. The map, which shows all the observed NotI and SmaI sites (six and 21, respectively) and 8 of approximately 30 SalI sites, is circular and yields a total size of 2.

View Article and Find Full Text PDF

The pulsed-field gel electrophoresis (PFGE) pattern of SmaI digests of 29 strains of Lactococcus lactis subsp. lactis and subsp. cremoris were determined.

View Article and Find Full Text PDF

Conjugal matings were performed between Lactococcus lactis DRC1 (a lactose-fermenting (Lac+), bacteriocin-producing (Bac+) strain) and L. lactis HID113 (Lac- and Bac-). Transconjugant derivatives of HID113 were identified on the basis of lactose fermentation, resistance to the DRC1 bacteriocin (dricin) or reduced sensitivity to phage sk1.

View Article and Find Full Text PDF