Characterization of the heteropolysaccharides produced by Liquorilactobacillus sicerae CUPV261 and Secundilactobacillus collinoides CUPV237 isolated from cider.

Some lactic acid bacteria (LAB) strains isolated from alcoholic beverages are able to produce exopolysaccharides (EPS). The present work focuses on the physico-chemical characterization of the heteropolysaccharides (HePS) produced by Liquorilactobacillus sicerae CUPV261T (formerly known as Lactobacillus sicerae) and Secundilactobacillus collinoides CUPV237 (formerly known as Lactobacillus collinoides) strains isolated from cider. Genome sequencing and assembly enabled the identification of at least four putative HePS gene clusters in each strain, which correlated with the ability of both strains to secrete EPS. The crude EPS preparation from CUPV261T contained glucose, galactose and rhamnose, and that of CUPV237 was composed of glucose, galactose and N-acetylglucosamine. Both EPS were mixtures of HePS of different composition, with two major soluble components of average molecular weights (Mw) in the range of 106 and 104 g.mol-1. These HePS were resistant to gastric stress conditions in an in vitro model, and they significantly reduced zebrafish larvae mortality in an in vivo model of inflammatory bowel disease.

Modeling Root-Knot Nematode Regulation by the Biocontrol Fungus Pochonia chlamydosporia.

Two models of increasing complexity were constructed to simulate the interactions between the root-knot nematode (RKN) Meloidogyne incognita and the biocontrol fungus Pochonia chlamydosporia var. catenulata in a rhizosphere microcosm. The models described discrete population dynamics at hourly rates over a 6-month period and were validated using real parasitism and nematode or fungus data. A first, general Pochonia-nematode-root model (GPNR) used five functions and 16 biological constants. The variables and constants describing the RKN life cycle included the rates of egg production, hatching, juvenile (J2), and mature female development, including root or nematode self-density-dependent factors. Other constants accounted for egg parasitism, nematode-induced root losses, growth, and mortalities. The relationship between nematodes and fungal propagules showed density dependence and cyclic variations in time, including an attractor on the propagules and J2 phases space. The simulations confirmed a P. chlamydosporia optimal initial density of 5 · 103 propagules · cc soil-1, as usually applied in assays. The constants used in GPNR showed adherence to the nematode biology, with 103 eggs per egg mass, a 10-day average lifespan of J2, with 2 days required to enter roots, and adult lifespan lasting 24 days. The fungus propagule lifespan was 25 days, with an average feeder root lifespan lasting around 52 days. A second, more complex Pochonia-nematode-root detailed model (GPNRd) was then constructed using eight functions and 23 constants. It was built as GPNR did not allow the evaluation of host prevalence. GPNRd allowed simulations of all RKN life stages and included non-parasitic and parasitic fungus population fractions. Both GPNR and GPNRd matched real J2 and fungus density data observed in a RKN biocontrol assay. Depending on the starting conditions, simulations showed stability in time, interpreted as effective host regulation. GPNRd showed a fungus cyclic relationship with the J2 numbers, with prevalence data close to those observed (38.3 vs. 39.4%, respectively). This model also showed a further density-independent nematode regulation mechanism based on the P. chlamydosporia switch from a non-parasitic to a parasitic trophic behavior. This mechanism supported the biocontrol of M. incognita, also sustained by a concomitant increase of the root density.

Characterization of Pediococcus ethanolidurans CUPV141: A ß-D-glucan- and Heteropolysaccharide-Producing Bacterium.

Pediococcus ethanolidurans CUPV141 is an exopolysaccharide (EPS)-producing lactic acid bacterium, first isolated from Basque Country cider (Spain). Physicochemical analysis of the EPS synthesized by the bacterium revealed that CUPV141 produces mostly a homopolysaccharide (HoPS), characterized as a 2-substituted (1,3)-ß-D-glucan, together with a small quantity of a heteropolysaccharide (HePS) composed of glucose, galactose, glucosamine, and glycerol-3-phosphate, this being the first Pediococcus strain described to produce this kind of polymer. On the contrary, an isogenic strain CUPV141NR, generated by chemical mutagenesis of CUPV141, produced the HePS as the main extracellular polysaccharide and a barely detectable amount of 2-substituted (1,3)-ß-D-glucan. This HoPS is synthesized by the transmembrane GTF glycosyltransferase (GTF), encoded by the gtf gene, which has been previously reported to be located in the pPP2 plasmid of the Pediococcus parvulus 2.6 strain. Southern blot hybridization revealed that in CUPV141 the gtf gene is located in a plasmid designated as pPE3, whose molecular mass (34.4 kbp) is different from that of pPP2 (24.5 kbp). Analysis of the influence of the EPS on the ability of the producing bacteria to adhere to the eukaryotic Caco-2 cells revealed higher affinity for the human enterocytes of CUPV141NR compared to that of CUPV141. This result indicates that, in contrast to the 2.6 strain, the presence of the HoPS does not potentiate the binding ability of P. ethanolidurans. Moreover, it supports that the phosphate-containing bacterial HePS improved the interaction between P. ethanolidurans and the eukaryotic cells.

Draft Genome Sequence of Pediococcus parvulus 2.6, a Probiotic ß-Glucan Producer Strain.

We report here the draft genome sequence of the probiotic Pediococcus parvulus 2.6, a lactic acid bacterial strain isolated from ropy cider. The bacterium produces a prebiotic and immunomodulatory exopolysaccharide, and this is the first strain of the P. parvulus species whose genome has been characterized.

Draft Genome Sequence of Lactobacillus collinoides CUPV237, an Exopolysaccharide and Riboflavin Producer Isolated from Cider.

Lactobacillus collinoides CUPV237 is a strain isolated from a Basque cider. Lactobacillus collinoides is one of the most frequent species found in cider from Spain, France, or England. A notable feature of the L. collinoides CUPV237 strain is its ability to produce exopolysaccharides.

Production and partial characterization of exopolysaccharides produced by two Lactobacillus suebicus strains isolated from cider.

Many lactic acid bacteria synthesize extracellular polysaccharides (exopolysaccharides, EPSs) with a large variation in structure and potential functional properties. Although EPS production can produce detrimental effects in alcoholic beverages, these polymers play an important role in the rheological behavior and texture of fermented products. In this work, EPS production by two Lactobacillus suebicus strains, which were isolated from ropy ciders, was examined in a semidefined medium. The existence of priming glycosyltransferase encoding genes was detected by PCR. In addition, the preliminary characterization of the polymers was undertaken. Molecular masses were determined by size exclusion chromatography revealing the presence of two peaks, corresponding to polymers of high- and low-molecular-weight in all fractions. The composition of the EPS fractions was analyzed by gas chromatography-mass spectrometry after acid hydrolysis, revealing that they contained glucose, galactose, N-acetylglucosamine and phosphate, although in different ratios, suggesting that a mixture of polysaccharides is being synthesized. We also examined the influence of the sugar source (glucose, ribose, xylose, or arabinose) and pH conditions on growth and EPS production.

Polyphenolic profile in cider and antioxidant power.

BACKGROUND: The aim of this work was to find the effect of polyphenolic compounds in Basque ciders on the following parameters: antioxidant activity, browning, protein-precipitating capacity, turbidity and reduction potential. These five parameters are highly important, as they affect the taste, the visual aspect and the preservation of cider, and are mainly related to polyphenolic compounds. RESULTS: Procyanidin B1 and procyanidin B2 showed a significant positive effect on antioxidant activity. p-Coumaric acid, (-)-epicatechin and hyperin had a significant positive effect on protein-precipitating capacity. Tyrosol had a significant negative effect on reduction potential. CONCLUSION: Procyanidin B1 and procyanidin B2 are the most powerful antioxidants in Basque cider, while p-coumaric acid, (-)-epicatechin and hyperin are those with greatest capacity to precipitate proteins. Ciders with higher tyrosol concentration will have less reduction potential and higher antioxidant reservoir.

Lactobacillus sicerae sp. nov., a lactic acid bacterium isolated from Spanish natural cider.

Strains CUPV261(T) and CUPV262 were isolated from ropy natural ciders of the Basque Country, Spain, in 2007. Cells are Gram-stain positive, non-spore-forming, motile rods, facultative anaerobes and catalase-negative. The strains are obligately homofermentative (final product dl-lactate) and produce exopolysaccharides from sucrose. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the highest similarity to both isolates corresponded to the type strain of Lactobacillus vini (99.1 %), followed by Lactobacillus satsumensis (96.4 %), and Lactobacillus oeni (96.2 %), and for all other established species, 16S rRNA gene sequence similarities were below 96 %. The species delineation of strains CUPV261(T) and CUPV262 was evaluated through RAPD fingerprinting. In addition, a random partial genome pyrosequencing approach was performed on strain CUPV261(T) in order to compare it with the genome sequence of Lactobacillus vini DSM 20605(T) and calculate indexes of average nucleotide identity (ANI) between them. Results permit the conclusion that strains CUPV261(T) and CUPV262 represent a novel species of the genus Lactobacillus, for which the name Lactobacillus sicerae sp. nov. is proposed. The type strain is CUPV261(T) ( = CECT 8227(T) = KCTC 21012(T)).

Craneomaxilar cervical en pacientes clase II división 1: cambio de diámetro transverso / Cervical headgear for the treatment of class II division 1 malocclusion: modification of arch transverse diameter

PROPOSITO: Evaluar los cambios del diámetro transverso del arco de paciente clase II división 1, tratados y no tratados con un craneomaxilar de tracción cervical, para reconocer si el craneomaxilar tiene algún efecto significativo sobre el crecimiento transverso del maxilar superior, en un periodo aproximado de 9 meses, al compararlo con las modificaciones fisiológicas del crecimiento y desarrollo. METODOS: se utilizo una muestra de 26 pacientes(13 con craneomaxilar y 13 sin tratamiento), seleccionados de manera intencional de acuerdo con las características especificas de clase II división 1. Se correlacionaron la edad, el género y el tratamiento con un craneomaxilar de tracción cervical. Se tomaron medidas iniciales del diámetro transverso del arco en modelos de estudio, y a los 4 y 9 meses y posteriores a la realización del tratamiento y de igual forma a los modelos de los pacientes no tratados. Para el análisis de la información, se aplicó la U de Mann Whitney. RESULTADOS: se hallaron diferencias significativas en cuanto a la variación del diámetro transverso en pacientes con craneomaxilar . Con respecto a la edad, en los pacientes con craneomaxilar, las variaciones fueron mayores en el rango de edad de 7-10 para la medida intercanina y mayores de rango de 11-13 para la medida intermolar. Para aquellos sin craneomaxilar, ambas medidas mostraron mayores aumentos para el rango de 7-10 años. En cuanto al género, los mayores cambios en pacientes con craneomaxiliar ocurrieron en las niñas a diferencia de aquellos sin aparatología, que ocurrió en los niños (p<0.05.