Collagen type I from bovine bone. Effect of animal age, bone anatomy and drying methodology on extraction yield, self-assembly, thermal behaviour and electrokinetic potential.

Natural collagen is easily available from animal tissues such as bones. Main limitations reported in the use of natural collagen are heterogeneity and loss of integrity during recovery. However, its natural complexity, functionality and bioactivity still remain to be achieved through synthetic and recombinant ways.

Influence of sourdough prefermentation, of steam cooking suppression and of decreased sucrose content during wheat flakes processing on the plasma glucose and insulin responses and satiety of healthy subjects.

Background: Ready-to-eat breakfast cereals (RTE-BC) are eaten more and more frequently by both adults and adolescents, but their nutritional quality is far from satisfactory: they often contained too much sugars and lead to a high glycemic index (GI) which generally contributes to a more rapid return of the feeling of hunger favouring nibbling in the morning.

Objective: To reduce the GI and to improve the nutritional quality of standard wheat flakes (SWF) by adding a sourdough prefermentation step, suppressing steam cooking and decreasing the sucrose content (MWF, modified wheat flake).

Methods: Eleven healthy male volunteers were randomly given, at three separate times, SWF, MWF, and white-wheat bread (WWB, reference food).

Surface migration of Staphylococcus xylosus on low-agar media.

Staphylococcus xylosus is a commensal species commonly found on the skin of mammals, but also currently used as starter culture for meat fermentation. Most strains of this species colonize by forming a biofilm on abiotic surfaces. We show here that the majority of S.

Isolation and characterization of cultivable fermentative bacteria from the intestine of two edible snails, Helixpomatia and Cornu aspersum (Gastropoda: Pulmonata).

The intestinal microbiota of the edible snails Cornu aspersum fSyn: H. aspersa), and Helix pomatia were investigated by culture-based methods, 16S rRNA sequence analyses and phenotypic characterisations. The study was carried out on aestivating snails and two populations of H.

A new device for rapid evaluation of biofilm formation potential by bacteria.

This work describes the implementation of a new assay named the BioFilm Ring Test to evaluate the ability of bacteria to form biofilms. This assay is based on the immobilisation (or not) of magnetic beads embedded by bacterial aggregates or mats (patented concept). It is realised on modified polystyrene 96-wells microtiter plates with individual 8-wells slides.

Surface properties and behaviour on abiotic surfaces of Staphylococcus carnosus, a genetically homogeneous species.

This work aimed to characterize the surface properties of Staphylococcus carnosus and the influence of different media on their ability to adhere and grow on industrial supports. As their colonization could be dependant of the strain, the genetic diversity of the strains was studied. The diversity of 13 strains analysed by pulsed-field gel electrophoresis revealed that the S.

Growth arrest and decrease of alpha-SMA and type I collagen expression by palmitic acid in the rat hepatic stellate cell line PAV-1.

Liver fibrosis is characterized by an activation of hepatic stellate cells (HSC). During primary culture HSC evolve from a quiescent into an activated phenotype which is characterized by alpha-smooth muscle actin (alpha-SMA) up-regulation, increase in cell growth, and extracellular matrix secretion. HSC culture with trans-resveratrol can lead to deactivation of myofibroblast-like HSC.

Formation of biofilm by Staphylococcus xylosus.

The ability of 12 Staphylococcus xylosus strains to form biofilm was determined through the study of different criteria. Eleven out of the 12 strains were able to form biofilm, 10 preferentially on hydrophilic support (glass) and one, S. xylosus C2a, on both hydrophilic and hydrophobic (polystyrene) supports.

The Ruminococcus albus pilA1-pilA2 locus: expression and putative role of two adjacent pil genes in pilus formation and bacterial adhesion to cellulose.

Ruminococcus albus produces fimbria-like structures that are involved with the bacterium's adhesion to cellulose. The subunit protein has been identified in strain 8 (CbpC) and strain 20 (GP25) and both are type IV fimbrial (Pil) proteins. The presence of a pil locus that is organized similarly in both strains is reported here together with the results of an initial examination of a second Pil protein.

Interaction between H2-producing and non-H2-producing cellulolytic bacteria from the human colon.

The cellulose-degrading species recently isolated from the human colon showed diverse ability to degrade and ferment cellulose. In the present study, the nature of the inter-relation existing between one H(2)-producing cellulolytic isolate (Ruminococcus sp. nov.

Antimicrobial effects of sanitizers against planktonic and sessile Listeria monocytogenes cells according to the growth phase.

This study was designed to investigate the individual or combined effects of sanitizers on survival of planktonic or sessile Listeria monocytogenes cells at different phase of growth. The sanitizers tested included: (i) acetic acid (pH 5.0), (ii) NaOH (pH 12.

Adhesion to cellulose of the Gram-positive bacterium Ruminococcus albus involves type IV pili.

This study was aimed at characterizing a cell-surface 25 kDa glycoprotein (GP25) that was previously shown to be underproduced by a spontaneous adhesion-defective mutant D5 of Ruminococcus albus 20. An antiserum against wild-type strain 20 was adsorbed with the mutant D5 to enrich it in antibodies 'specific' to adhesion structures of R. albus 20.

Characterization of a spontaneous adhesion-defective mutant of Ruminococcus albus strain 20.

A spontaneous adhesion-defective mutant (mutant D5) of Ruminococcus albus strain 20 was isolated and compared to the parent to investigate the impact of the mutation on cellulolysis and to identify the adhesion mechanism of R. albus. The comparison of kinetics of cellulose degradation by strain 20 and mutant D5 showed that the mutation delayed and reduced bacterial growth on cellulose and cellulose degradation.

Full capacity of recombinant Escherichia coli heat-stable enterotoxin fusion proteins for extracellular secretion, antigenicity, disulfide bond formation, and activity.

We have successfully used the major subunit ClpG of Escherichia coli CS31A fimbriae as an antigenic and immunogenic exposure-delivery vector for various heterologous peptides varying in nature and length. However, the ability of ClpG as a carrier to maintain in vitro and in vivo the native biological properties of passenger peptide has not yet been reported. To address this possibility, we genetically fused peptides containing all or part of the E.

Location by fluorescence microscopy of glycosidases and a xylanase in the anaerobic gut fungi Caecomyces communis, Neocallimastix frontalis, and Piromyces rhizinflata.

beta-D-Glucosidase, beta-D-fucosidase, beta-D-xylosidase, and beta-D-cellobiopyranosidase activities in Caecomyces communis, Neocallimastix frontalis, and Piromyces rhizinflata, located with fluorescent conjugates, occur throughout the whole thallus as from zoospore germination and disappear before sporulation. beta-D-Galactosidase and alpha-L-arabinopyranosidase activities are low or nonexistent. A xylanase, detected by indirect immunofluorescence, was observed at the surface of the vegetative cells, vesicles, or rhizoids.

Permissible peptide insertions surrounding the signal peptide-mature protein junction of the ClpG prepilin: CS31A fimbriae of Escherichia coli as carriers of foreign sequences.

The clpG gene, expressing the Escherichia coli major CS31A fimbrial subunit ClpG, was subjected to random mutagenesis by insertion of an EcoRI linker and a kanamycin-resistance (KmR) cassette into the multiple newly generated EcoRI sites. The KmR gene was then excised by PstI, which left a 48-bp linker representing the heterologous sequence. The same procedure was followed to introduce a synthetic oligodeoxyribonucleotide (oligo) corresponding to epitope C from the spike protein S from the porcine transmissible gastroenteritis coronavirus (TGEV).

Scanning and transmission electron microscopic study of adherence of Escherichia coli O103 enteropathogenic and/or enterohemorrhagic strain GV in enteric infection in rabbits.

The GV strain (serotype O103:H2:K-), originally isolated from a diarrheic rabbit, is an enteropathogenic Escherichia coli strain that produces diarrhea without synthesizing the classical enterotoxins and that is not invasive. This strain is characterized by a 117-kb plasmid (pREC-1). Histological study of the gut by scanning electron microscopy and transmission electron microscopy was performed on the GV strain, on a derivative strain cured of pREC-1, and on transconjugants obtained by transfer of pREC-1 to nonpathogenic strains E.

Piromyces rhizinflata nov. sp., a strictly anaerobic fungus from faeces of the Saharian ass: a morphological, metabolic and ultrastructural study.

A new species of strictly anaerobic chytridiomycete was isolated from dried faeces of the Saharian ass that had been stored for up to 150 days. Because of its monocentric thallus and uniflagellate zoospores it belongs to the genus Piromyces. It exhibits a high affinity for P.

Anaeromyces mucronatus nov. gen., nov. sp. A new strictly anaerobic rumen fungus with polycentric thallus.

A new species of strictly anaerobic fungus was isolated from the cow rumen. It is characterized by a polycentric thallus, a polynuclear rhizomycelium, mucronate zoosporangia and uniflagellated zoospores. It is also singular in that the sporocysts do not react to the specific lectins of L-fucose, N-acetyl-D-galactosamine and diacetyl chitobiose.

Use of lectins for a comparative study of cell wall composition of different anaerobic rumen fungal strains.

The technique based on fluorescein-linked lectins used to determine the cell wall structure of anaerobic rumen fungi belonging to genera: Neocallimastix, Piromonas and Sphaeromonas, appears to be an interesting tool for distinguishing between strains. Furthermore this technique shows differences of cell wall composition between different parts of the thallus (spores, sporangia, rhizoïds).