Antibacterial activity of wine phenolic compounds and oenological extracts against potential respiratory pathogens.

AIMS: To investigate the effect of seven wine phenolic compounds and six oenological phenolic extracts on the growth of pathogenic bacteria associated with respiratory diseases (Pseudomonas aeruginosa, Staphylococcus aureus, Moraxella catarrhalis, Enterococcus faecalis, Streptococcus sp Group F, Streptococcus agalactiae and Streptococcus pneumoniae). METHODS AND RESULTS: Antimicrobial activity was determined using a microdilution method and quantified as IC(50) . Mor. catarrhalis was the most susceptible specie to phenolic compounds and extracts. Gallic acid and ethyl gallate were the compounds that showed the greatest antimicrobial activity. Regarding phenolic extracts, GSE (grape seed extract) and GSE-O (oligomeric-rich fraction from GSE) were the ones that displayed the strongest antimicrobial effects. CONCLUSIONS: Results highlight the antimicrobial properties of wine phenolic compounds and oenological extracts against potential respiratory pathogens. The antimicrobial activity of wine phenolic compounds was influenced by the type of phenolic compounds. Gram-negative bacteria were more susceptible than Gram-positive bacteria to the action of phenolic compounds and extracts; however, the effect was species-dependent. SIGNIFICANCE AND IMPACT OF STUDY: The ability to inhibit the growth of respiratory pathogenic bacteria as shown by several wine phenolic compounds and oenological extracts warrants further investigations to explore the use of grape and wine preparations in oral hygiene.

Consensus statements from the Workshop 'Probiotics and Health: Scientific Evidence' / Declaraciones consensuadas del Workshop: “Probióticos y Salud: Evidencia Científica”

This report shows the level of scientific consensus on definition, characteristics and health benefits of probiotics. The content of the report has derived from the scientific meeting: Workshop on Probiotics and Health. Scientific evidence, that congregated several Spanish experts, including gastroenterologists, microbiologists, nutritionists, immunologists and food technologists, among others, who have agreed with the statements shown in this document. Each statement has been sustained with the most relevant scientific aspects that were discussed during the Workshop and the following evaluation of there port by all experts who approved and signed it (AU)

En este documento se muestra una base de consenso entorno a la definición, características y propiedades beneficiosas de los probióticos. El contenido fue generado a partir de la reunión científica Workshop Probióticos y Salud. Evidencia Científica, que agrupó a una variedad de expertos españoles gastroenterólogos, microbiólogos, nutricionistas, inmunólogos y tecnólogos de alimentos, entre otros, que se han adherido en su mayoría a las sentencias que constituyen este documento. Para cada sentencia se establecen las aspectos científicos más relevantes que la respaldan y que son consecuencia del acuerdo al que se ha llegado tras el debate surgido en la reunión y la evaluación posterior del contenido por todos los expertos que han firmado este documento (AU)

Biological and molecular characterization of a two-peptide lantibiotic produced by Lactococcus lactis IFPL105.

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, respectively. The genes encoding the two peptides were cloned and sequenced and were found to be identical to the ltnAB genes from plasmid pMRC01 of L. lactis DPC3147. LtnA and LtnB contain putative leader peptide sequences similar to the known 'double glycine' type. The predicted amino acid sequence of mature LtnA and LtnB differed from the amino acid content determined for the purified alpha and beta peptides in the residues serine, threonine, cysteine and alanine. Post-translational modification, and the formation of lanthionine or methyllanthionine rings, could partly explain the difference. Hybridization experiments showed that the organization of the gene cluster in pBAC105 responsible for the production of the bacteriocin is similar to that in pMRC01, which involves genes encoding modifying enzymes for lantibiotic biosynthesis and dual-function transporters. In both cases, the gene clusters are flanked by IS946 elements, suggesting an en bloc transposition. The findings from the isolation and molecular characterization of the bacteriocin provide evidence for the lantibiotic nature of the two peptides.

Salt balance and rennet clotting properties of cow's, ewe's, and goat's milks preserved with carbon dioxide.

Cow's, ewe's, and goat's milk samples were treated with carbon dioxide gas until a pH of 6.1 was reached and stored at 4 degrees C to determine the resulting modifications in the mineral balance. The amounts of calcium and phosphorus dissolved during the acidification were similar in the three species. The acidification with CO2 produced the dissolution of phosphorus and magnesium in concentrations similar to those attained by acidification with lactic acid or hydrochloric acid. Still, the contents of soluble calcium and ionic calcium were higher with the CO2 treatment. The increase of ionic calcium due to the addition of CO2 could explain why milk subjected to such treatment is better suited for coagulation. Removal of added CO2 by shaking the milk for several hours at atmospheric pressure resulted in a higher concentration of ionic-calcium than was found in control milks to which no CO2 had been added. Thus the addition of CO2 improved milk's technological suitability for cheesemaking.