Suchergebnisse

[Excerpt] Bacterial vaginosis (BV) is the most prevalent vaginal disorder in women of childbearing age, posing some significant health risks, such as abnormal pregnancy, pelvic inflammatory disease and an increased risk of sexual transmitted infections, including HIV [1]. It is characterized by a disruption in the normal balance of bacteria in the vagina with a reduction on lactobacilli number and an overgrowth of anaerobes [2]. Despite several species have been associated with this condition [3], several studies point out for the higher virulence potential of Gardnerella vaginalis [4, 5, 6] and therefore it has been proposed as the main etiological candidate of BV. Current BV treatment is based in antibiotic therapy leading to an increased resistance of BV anaerobes and to a severe reduction of healthy lactobacilli strains in the vaginal epithelium [7, 8, 9]. Therefore, a more appropriate treatment is required, aiming to decrease G. vaginalis and also to promote the lactobacilli re-colonization in BV patients [10]. Previous studies have shown the potential of lactobacilli in preventing vaginal colonization by pathogens [11, 12] through different mechanisms, which may include auto-aggregation, co-aggregation with pathogenic microorganisms, adhesion to epithelial cells and/or by the production of some metabolites (such as lactic acid, hydrogen peroxide, bacteriocins, bacteriocin-like proteins and biosurfactants) [13]. Thus, the probiotic properties of lactobacilli should be explore in order to evaluate their potential as a more effective treatment for BV. [.] ; The authors acknowledge the financial support by European Union funds (FEDER/COMPETE) and by national funds (FCT) under the project with reference FCOMP-01-0124-FEDER008991 (PTDC/BIA-MIC/098228/2008). ...

Lactobacillus species constitute one of the dominant and beneficial bacteria in our body and are used in developed countries as a microbial adjuvant. Identification of these probiotic bacteria is traditionally performed by culture-based techniques. However, such methods are very time-consuming and can give inaccurate results, especially when Lactobacillus is present in mixed bacterial complex communities. Our study aimed to accurately identify Lactobacillus spp. using a novel Peptide Nucleic Acid (PNA) Fluorescence In Situ Hibridization (FISH) probe. The probe (Lac663) was tested on 36 strains belonging to different Lactobacillus species and on 20 strains of other bacterial species. The sensitivity and specificity of the method were 100% (95% confidence interval (CI), 88.0 to 100.0%) and 95.0% (95% CI, 73.1 to 99.7%), respectively. Additionally, we tested the applicability of the method on milk samples added with Lactobacillus strains at probiotic range concentrations and others taxonomically related bacteria, as well as pathogenic bacteria. The Lac663 probe bound exclusively to Lactobacillus strains and the described PNA-FISH method was capable of directly quantifying Lactobacillus spp. in concentrations at which these potential probiotic bacteria are considered to have an effective benefit on human health. ; This work was supported by European Union funds (FEDER/COMPETE) and by national funds (FCT) under the project with reference FCOMP-01-0124-FEDER-008991 (PTDC/BIA-MIC/098228/2008. Antonio Machado acknowledges the FCT individual fellowship-SFRH/BD/62375/2009. However, it is important to refer that FCT did not have any role in the design of the experiments or manuscript ...

The synthesis of galacto-oligosaccharides (GOS) by the action of Aspergillus oryzae β-galactosidase free and immobilized on magnetic polysiloxane-polyvinyl alcohol (mPOS-PVA) was studied. A maximum GOS concentration of 26% (w/v) of total sugars was achieved at near 55% lactose conversion from 50%, w/v lactose solution at pH 4.5 and 40 °C. Trisaccharides accounted for more than 81% of the total GOS produced. GOS formation was not considerably affected by pH and temperature. The concentrations of glucose and galactose encountered near maximum GOS concentration greatly inhibited the reactions and reduced GOS yield. GOS formation was not affected by enzyme immobilization in the mPOS-PVA matrix, indicating the absence of diffusional limitations in the enzyme carrier. Furthermore, this water insoluble magnetic derivative was reutilized 10-times and retained about 84% of the initial activity. In addition, the kinetic parameters for various initial lactose concentrations were determined and compared for the free and immobilized enzyme. ; David F. M. Neri gratefully acknowledges support by the Programme Alpan, the European Union Programme of High Level Scholarships for Latin America (Scholarship No. E05D057787BR). Luiz B. Carvalho Jr. is recipient of a scholarship of the Brazilian National Research Council ...

Background: Bacterial vaginosis (BV) is a common vaginal infection occurring in women of reproductive age. It is widely accepted that the microbial switch from normal microflora to BV is characterized by a decrease in vaginal colonization by Lactobacillus species together with an increase of Gardnerella vaginalis and other anaerobes. Our goal was to develop and optimize a novel Peptide Nucleic Acid (PNA) Fluorescence in situ Hybridization assay (PNA FISH) for the detection of Lactobacillus spp. and G. vaginalis in mixed samples. Results: Therefore, we evaluated and validated two specific PNA probes by using 36 representative Lactobacillus strains, 22 representative G. vaginalis strains and 27 other taxonomically related or pathogenic bacterial strains commonly found in vaginal samples. The probes were also tested at different concentrations of G. vaginalis and Lactobacillus species in vitro, in the presence of a HeLa cell line. Specificity and sensitivity of the PNA probes were found to be 98.0% (95% confidence interval (CI), from 87.8 to 99.9%) and 100% (95% CI, from 88.0 to 100.0%), for Lactobacillus spp.; and 100% (95% CI, from 92.8 to 100%) and 100% (95% CI, from 81.5 to 100.0%) for G. vaginalis. Moreover, the probes were evaluated in mixed samples mimicking women with BV or normal vaginal microflora, demonstrating efficiency and applicability of our PNA FISH. Conclusions: This quick method accurately detects Lactobacillus spp. and G. vaginalis species in mixed samples, thus enabling efficient evaluation of the two bacterial groups, most frequently encountered in the vagina. ; This work was supported by European Union funds (FEDER/COMPETE) and by national funds (FCT) under the project with reference FCOMP-01-0124-FEDER-008991 (PTDC/BIA-MIC/098228/2008). AM acknowledges the FCT individual fellowship - ...

Bioconversions using enzymes immobilized in magnetic supports present significant advantages due to the easy separation of the enzyme from the reaction mixture and the simplicity and low cost of the support preparation. The characterization of the oligosaccharide mixture obtained by the action of b-galactosidase covalently attached, via glutaraldehyde, to a hydrazideeDacronemagnetite composite is presented. The fractionation of the oligosaccharide mixture by high performance liquid chromatography, followed by the analysis of the purified compounds by mass spectrometry and nuclear magnetic resonance spectroscopy permitted the identification of glucose, galactose, lactose and a hexose disaccharide containing a 1/6 linkage. Also, the following GOS were identified: b-D-Galp-(1/6)-b-D-Galp-(1/4)- Glcp, b-D-Galp-(1/4)-[b-D-Galp-(1/6)]-Glcp and b-D-Galp-(1/6)-b-D-Galp-(1/6)-b-D-Galp-(1/4)- Glcp. When GOS yield (26.2%) and kinetics of biotransformation of lactose by the Dacron immobilized b-galactosidase were compared with values obtained for the enzyme immobilized in other magnetic supports, similar behaviour was observed ; David F.M. Neri gratefully acknowledges support by Alban, the European Union Programme of High Level Scholarships for Latin America (Scholarship No. E05D057787BR). Luiz B. Carvalho Jr. is recipient of a scholarship from the Brazilian National Research Council (CNPq). M.R.M. Domingues acknowledges financial support provided to the project POCI/QUI/59337/2004. Duarte P. M. Torres acknowledges Fundacao para a Ciencia e a Tecnologia (Portugal) for the PhD Grant received (reference ...

This paper gives an overview of development of the EU-bioeconomy, 2014-2020. The Vision of the new Circular Bio-based Economy, CBE is presented: Unlocking the full potential of all types of sustainably sourced biomass, crop residues, industrial side-streams, and wastes by transforming it into value-added products. The resulting product portfolio consists of a wide spectrum of value-added products, addressing societal and consumer needs. Food and feed, bio-based chemicals, materials, healthpromoting products; and bio-based fuels. The pillars of CBE are described, including biotechnology, microbial production, enzyme technology, green chemistry, integrated physical/chemical processing, policies, conducive framework conditions and public private partnerships. Drivers of CBE are analyzed: Biomass supply, biorefineries, value chain clusters, rural development, farmers, foresters and mariners; urgent need for climate change mitigation and adaptation, and stopping biodiversity loss. Improved framework conditions can be drivers but also obstacles if not updated to the era of circularity. Key figures, across the entire BBI-JU project portfolio (20142020) are provided, including expansion into biomass feedstocks, terrestrial and aquatic, and an impressive broadening of bio-based product portfolio, including higher-value, healthpromoting products for man, animal, plants and soil. Parallel to this, diversification of industrial segments and types of funding instruments developed, reflecting industrial needs and academic research involvement. Impact assessment is highlighted. A number of specific recommendations are given; e.g., including international win/win CBEcollaborations, as e.g., expanding African EU collaboration into CBE. In contrast to fossil resources biological resources are found worldwide. In its outset, circular biobased economy, can be implemented all over, in a just manner, not the least stimulating rural development ; This study received funding only for covering the production costs (carried by the public ...