Search

Mycobacterium tuberculosis produces mycolic acids which are relevant for persistence, recalcitrance to antibiotics and defiance to host immunity. c-di-GMP is a second messenger involved in transition from planktonic cells to biofilms, whose levels are controlled by diguanylate cyclases (DGC) and phosphodiesterases (PDE). The transcriptional regulator dosR, is involved in response to low oxygen, a condition likely happening to a subset of cells within biofilms. Here, we found that in M. bovis BCG, expression of both BCG1416c and BCG1419c genes, which code for a DGC and a PDE, respectively, decreased in both stationary phase and during biofilm production. The kasA, kasB, and fas genes, which are involved in mycolic acid biosynthesis, were induced in biofilm cultures, as was dosR, therefore suggesting an inverse correlation in their expression compared with that of genes involved in c-di-GMP metabolism. The relative abundance within trehalose dimycolate (TDM) of α-mycolates decreased during biofilm maturation, with methoxy mycolates increasing over time, and keto species remaining practically stable. Moreover, addition of synthetic c-di-GMP to mid-log phase BCG cultures reduced methoxy mycolates, increased keto species and practically did not affect α-mycolates, showing a differential effect of c-di-GMP on keto- and methoxy-mycolic acid metabolism.

Carotene cleavage dioxygenases (CCDs) are a large family of Fe

A novel nanocomposite whey protein-based film with nanoemulsified cocoa liquor (CL) was prepared using one-stage microfluidization to evaluate the emulsion properties and the effect of CL on the film properties by response surface methodology (RSM). The results indicated that the number of cycles by microfluidization had a significant effect (p &lt, 0.05) on the particle size and polydispersity of the nanoemulsion, with a polyphenol retention of approximately 83%. CL decreased the solubility (&lt, 21.87%) and water vapor permeability (WVP) (&lt, 1.57 g mm h−1 m−2 kPa−1) of the film. FTIR analysis indicated that CL modified the secondary protein structure of the whey protein and decreased the mechanical properties of the film. These results demonstrate that applying the film as a coating is feasible and effective to improve the shelf life of bakery products with a high moisture content. This nanocomposite film is easy to produce and has potential applications in the food industry.

BackgroundIn recent years, disease treatment has evolved strategies that require increase in pharmaceutical agent’s efficacy and selectivity while decreasing their toxicity in normal tissues. These requirements have led to the development of nanoscale liposome systems for drug release. This review focuses on lipid features, pharmacological properties of liposomal formulations and the clinical studies of their application.Main bodySeveral lipids are available, but their properties could affect pharmacological or clinical efficiency of drug formulations. Many liposomal formulations have been developed and are currently on the market. Proper selection of lipid is essential for the pharmacological effect to be improved. Most of the formulations use mainly zwitterionic, cationic or anionic lipids, PEG and/or cholesterol, which have different effects on stability, pharmacokinetics and delivery of the drug formulation. Clinical trials have shown that liposomes are pharmacologically and pharmacokinetically more efficient than drug-alone formulations in treating acute myeloid leukemia, hepatitis A, pain management, ovary, gastric breast and lung cancer, among others.ConclusionLiposomal formulations are less toxic than drugs alone and have better pharmacological parameters. Although they seem to be the first choice for drug delivery systems for various diseases, further research about dosage regimen regarding dose and time needs to be carried out.

Tuberculosis (TB) is the most important infectious disease worldwide, based on the number of new cases and deaths reported by the World Health Organization. Several vaccine candidates against TB have been characterized at preclinical and clinical levels. The BCGΔBCG1419c vaccine candidate, which lacks the BCG1419c gene that encodes for a c-di-GMP phosphodiesterase, provides improved efficacy against chronic TB, reactivation from latent-like infection and against chronic TB in the presence of type 2 diabetes in murine models. We previously reported that compared with wild type BCG, BCGΔBCG1419c changed levels of several proteins. Here, using a label-free proteomic approach, we confirmed that a novel, second-generation version of BCGΔBCG1419c maintains changes in antigenic proteins already reported, and here we further found differences in secreted proteins, as well as that this new BCGΔBCG1419c version modifies its production of proteins involved in redox and nitrogen/protein metabolism compared with wild type BCG. This work contributes to the proteomic characterization of a novel vaccine candidate that is more effective against TB than parental BCG in diverse murine models.

"En México, el 54 % de las aguas residuales no reciben tratamiento y son desalojadas hacia los cuerpos de agua, suelos y canales de riego lo que genera un fuerte problema de contaminación y un alto riesgo para la salud humana y la biota acuática. En las últimas décadas se han detectado los denominados contaminantes emergentes en aguas superficiales con presencia de aguas residuales crudas y tratadas. Estos compuestos y sus metabolitos reactivos causan severos efectos toxicológicos en los organismos acuáticos o microorganismos del suelo aún en bajas concentraciones. El objetivo del trabajo fue determinar las propiedades físicas y químicas: pH, conductividad eléctrica (CE), sólidos disueltos totales (SDT), Ca2+, Mg2+, Na+, boro (B), fósforo total (P), metales traza (Cu, Zn, Fe, Mn) e identificar y cuantificar los contaminantes emergentes (farmacéuticos y drogas de abuso) en los influentes y efluentes de la Planta de Tratamiento de Aguas Residuales (PTAR) de Morelia, utilizando metodologías estandarizadas, espectrofotometría de infrarrojo (FT-IR) y espectrometría de masas (ESI-MS-TOF). Los valores de pH, CE, SDT, relación de adsorción de sodio (RAS), B, P y metales traza se encontraron dentro de los límites marcados por la norma mexicana NOM-001-ECOL-1996 y directrices internacionales para reúso de aguas residuales en agricultura. Los contaminantes emergentes identificados por ESI-MS-TOF fueron tetraciclina, cefaclor, cefadroxilo, ampicilina, clonazepam, lormetazepam, secobarbital, maprotilina, levotiroxina, cis-androsterona, paracetamol, lidocaína, bromfeniramina, fexofenadina, amfetamina, morfina, benzoilecgonina, 11-nor-Δ9-THC-9-COOH, dimetilamfetamina, fenciclidina, metadona y polietilenglicol. La eficiencia de remoción de estos contaminantes en los efluentes fue de 25.8 %, con extremos de 0 y 74.5 % para el polietilenglicol y metadona, respectivamente"

Unconventional crude oil as heavy, extra heavy, bitumen, tight, and shale oils will meet 10% of worldwide needs for 2035, perhaps earlier. Petroleum companies will face problems concerning crude oil extraction, production, transport, and refining, and some of these are addressed by the use of surfactants and other chemicals. For example, water-in-crude oil emulsions are frequently found during the production of mature wells where enhanced recovery techniques have been deployed. Nevertheless, the selection of adequate surfactant, dosage, type of water (sea, tap or oilfield), kind of crude oil (light, heavy, extra heavy, tight, shale, bitumen) affect the effectivity of treatment and usual bottle tests give limited information. We developed a fluorescence technique to study the effect of surfactants on medium, heavy, and extra heavy crude oil employing the natural fluorophore molecules from petroleum. We first carried out the characterization of commercial and synthetic surfactants, then dispersions of petroleum in water were studied by steady-state fluorometry and the size of petroleum aggregates were measured. The aggregation of petroleum incremented from medium to extra heavy crude oil and we discussed the effect of different surfactants on such aggregation.

The growing interest in bioactive compounds, especially in polyphenols, is due to their abundance in the human diet and potentially positive effects on health. The consumption of polyphenols has been shown to possess anti-diabetic properties by preventing insulin resistance or insulin secretion through different signaling pathways, this effect is associated with their capacity to exert genomic modulations. Several studies have suggested that polyphenols could also bind to cellular proteins and modulate their activity, however, the mechanisms of action underlying their beneficial effects are complex and are not fully understood. The aim of this work was to characterize phenolic compounds present in blue corn and black bean extracts as well as identify their potential interactions with target proteins involved in diabetes pathogenesis using in silico approach. Total polyphenols content of both blue corn and black beans was identified using UPLC-ESI/qTOF/MS and quantified by colorimetric assays. In this work we identified twenty-eight phenolic compounds in the extracts, mainly anthocyanins, flavonols, hydroxycinamic acids, dihydroxybenzoic acids, flavones, isoflavones, and flavanols. Interactome of these compounds with thirteen target proteins involved in type 2 diabetes mellitus was performed in-silico. In total, 312 bioactive compounds/protein interaction analyses were acquired. Molecular docking results highlighted that nine of the top ten interactions correspond to anthocyanins, cyanidin 3-glucoside with 11β-HS, GFAT, PPARG; delphinidin 3-glucoside with 11β-HS, GFAT, PTP and RTKs; and petunidin 3-glucoside with 11β-HS and PTP. These proteins are involved in mechanisms regulating functions such as inflammation, insulin resistance, oxidative stress, glucose and lipid metabolism. In conclusion, this work provides a prediction of the potential molecular mechanism of black bean and blue corn polyphenols, specifically anthocyanins and could constitute new pathways by which compounds exert their antidiabetic benefits., Food science, Nutrition Natural product chemistry Diabetes Polyphenols Black bean Blue corn Molecular docking.

Carotenoid cleavage dioxygenases (CCDs) are enzymes that have been implicated in the biosynthesis of a wide diversity of secondary metabolites with important economic value, including bixin. Bixin is the second most used pigment in the world’s food industry worldwide, and its main source is the aril of achiote (Bixa orellana L.) seeds. A recent transcriptome analysis of B. orellana identified a new set of eight CCD members (BoCCD4s and BoCCD1s) potentially involved in bixin synthesis. We used several approaches in order to discriminate the best candidates with CCDs genes. A reverse transcription-PCR (RT-qPCR) expression analysis was carried out in five developmental stages of two accessions of B. orellana seeds with different bixin contents: (P13W, low bixin producer and N4P, high bixin producer). The results showed that three BoCCDs (BoCCD4-1, BoCCD4-3, and BoCCD1-1) had an expression pattern consistent with bixin accumulation during seed development. Additionally, an alignment of the CCD enzyme family and homology models of proteins were generated to verify whether the newly proposed CCD enzymes were bona fide CCDs. The study confirmed that these three enzymes were well-preserved and belonged to the CCD family. In a second selection round, the three CCD genes were analyzed by in situ RT-qPCR in seed tissue. Results indicated that BoCCD4-3 and BoCCD1-1 exhibited tissue-specific expressions in the seed aril. To test whether the two selected CCDs had enzymatic activity, they were expressed in Escherichia coli; activity was determined by identifying their products in the crude extract using UHPLC-ESI-QTOF-MS/MS. The cleavage product (bixin aldehyde) was also analyzed by Fourier transform infrared. The results indicated that both BoCCD4-3 and BoCCD1-1 cleave lycopene in vitro at 5,6-5′,6′.

There is a growing interest in the identification of chemometric markers that allow the distinction and authentication of dark-chocolates according to their cocoa geographical origin and/or genotype. However, samples derived from Latin American cocoa, including specimens from North and South America, have not been studied in this context. An exploration of the melting behavior, fat composition, bioactive content, and volatile profile of commercial darkchocolates was conducted to identify possible patterns related to the genotype and/or origin of cocoa from Latin America. The melting properties were evaluated by DSC and related to fat content and fatty acids profile. Total polyphenol, anthocyanin, methylxanthine, and catechin content were analyzed. Finally, the volatile compounds were extracted and identified by HS-SPME/GC-MS and were analyzed through Principal Component Analysis (PCA) and the Hierarchical Cluster Analysis Heatmap (HCA Heatmap). The fatty acids profile showed a relationship with the melting properties of dark chocolate. The samples exhibited two glass-transition temperatures (Tg) at ≈19 °C and ≈25.5 °C, possibly related to traces of unstable polymorphic forms of monounsaturated triacylglycerides. The analysis of bioactive compounds demonstrated great variability among samples independent of the cocoa origin, genotype, and content. The PCA and HCA Heatmaps allowed discriminating against the chocolates in relation to the cocoa origin and genotype. Compounds like tetramethylpyrazine, trimethylpyrazine, benzaldehyde, and furfural could be considered as dark-chocolate aroma markers derived from Latin American cocoas (North American region). The 2-phenylethyl alcohol, 2-methylpropanoic acid, 2,3-butanediol, 2-nonanone, and limonene for derived from South America. And the 2-phenylethyl acetate, 3-methyl-butanal, and cinnamaldehyde could allow to distinguishing between regional genotypes.

The author's final peer reviewed version can be found by following the URI link. The Publisher's final version can be found by following the DOI link. Diabetes mellitus is a chronic disease characterized by high levels of glucose in the blood, which leads to metabolic disorders with severe consequences. Today, there is no cure for diabetes. The current management for diabetes and derived medical conditions, such as hyperglycemia, cardiovascular diseases, or diabetic foot ulcer, includes life style changes and hypoglycemia‐based therapy, which do not fully restore euglycemia or the functionality of damaged tissues in patients. This encourages scientists to work outside their boundaries to develop routes that can potentially tackle such metabolic disorders. In this regard, acellular and cellular approaches have represented an alternative for diabetics, although such treatments still face shortcomings related to limited effectiveness and immunogenicity. The advent of biomaterials has brought significant improvements for such approaches, and three‐dimensional extracellular matrix analogs, such as hydrogels, have played a key role in this regard. Advanced hydrogels are being developed to monitor high blood glucose levels and release insulin, as well as serve as a therapeutic technology. Herein, the state of the art in advanced hydrogels for improving treatment of diabetes, from laboratory technology to commercial products approved by drug safety regulatory authorities, will be concisely summarized and discussed.

Through force spectroscopy, we use an atomic force microscope (AFM) to compare the forces between two extra heavy crude oil (EHCO) droplets. This is done in various aqueous environments in order to compare said forces in the presence of a variety of surfactants and ionic species. A crude oil droplet is attached to the AFM cantilever and pressed against other droplets placed on a substrate. Differences in the behavior of the forces as a function of surfactant chemistry, concentration and the velocity of the approach and retract of the droplets are observed for droplets with a range of diameters 10

BACKGROUND The search for natural, novel, high-quality, stable food ingredients is an ongoing practice in the food industry. Pulp of borojo (Borojoa patinoi Cuatrecasas), which is a fruit of the Colombian Pacific region, can be separated into three phases: liquid (LP), medium (MP) and solid (SP) phases. The objective of this work was to evaluate the effect of the three-phase composition and gum arabic on their glass transitions temperatures (Tg). The best mixture, LP-MP, MP-SP and LP-SP and gum arabic (GA) was identified by response surface methodology. RESULTS When adding GA to SP borojo phase in a 1:1 proportion, the resulting Tg of the mixture was 132.27 °C whereas Tg for GA and SP-phase were 154.89 °C and 79.86 °C respectively, which supported this combination as attractive from a processing perspective and supports an industrial advantage of using borojo as food ingredient. Phases were characterized by high-performance liquid chromatography, Fourier transform infrared spectroscopy, confocal laser scanning microscopy and mass spectrometry. Low molecular weight compounds such as fructose for MP lowered Tg whereas the presence of lignin increased Tg of the mixtures as with the SP. CONCLUSIONS The addition of GA significantly increased Tg of borojo phases so leading to propose them as novel food processing materials. © 2015 Society of Chemical Industry

Pellicles, a type of biofilm, have gathered a renewed interest in the field of tuberculosis as a structure that mimics some characteristics occurring during M. tuberculosis infection, such as antibiotic recalcitrance and chronicity of infection, and as a source of antigens for humoral response in infected guinea pigs. In other bacteria, it has been well documented that the second messenger c-di-GMP modulates the transition from planktonic cells to biofilm formation. In this work, we used the live vaccine Mycobacterium bovis BCG to determine whether deletion of genes involved in c-di-GMP metabolism would affect interaction with macrophages, capacity to induce immune response in a murine cell line and mice, and how the protein profile was modified when grown as surface pellicles. We found that deletion of the BCG1419c (Delta c-di-GMP phosphodiesterase, ΔPDE) gene, or deletion of the BCG1416c (Delta c-di-GMP diguanylate cyclase, ΔDGC) gene, altered production of TNF-α, IL-6, and IL-1β, in murine macrophages, and resulted in attenuation in intra-macrophage replication. Moreover, in addition to the improved immunogenicity of the BCGΔBCG1419c mutant already reported, deletion of the BCG1416c gene leads to increased T CD4+ and T CD8+ activation. This correlated with protection versus lethality in mice infected with the highly virulent M. tuberculosis 5186 afforded by vaccination with all the tested BCG strains, and controlled the growth of the mildly virulent M. tuberculosis H37Rv in lungs by vaccination with BCGΔBCG1419c during chronic late infection from 4 to 6 months after challenge. Furthermore, when grown as surface pellicles, a condition used to manufacture BCG vaccine, in comparison to BCG wild type, both rBCGs changed expression of antigenic proteins such as DnaK, HbhA, PstS2, 35KDa antigen, GroEL2, as well as AcpM, a protein involved in synthesis of mycolic acids, molecules relevant to modulate inflammatory responses.

Background Assembly of recombinant capsid proteins into virus-like particles (VLPs) still represents an interesting challenge in virus-based nanotechnologies. The structure of VLPs has gained importance for the development and design of new adjuvants and antigen carriers. The potential of Tobacco etch virus capsid protein (TEV CP) as adjuvant has not been evaluated to date. Findings Two constructs for TEV CP expression in Escherichia coli were generated: a wild-type version (TEV-CP) and a C-terminal hexahistidine (His)-tagged version (His-TEV-CP). Although both versions were expressed in the soluble fraction of E. coli lysates, only His-TEV-CP self-assembled into micrometric flexuous filamentous VLPs. In addition, the His-tag enabled high yields and facilitated purification of TEV VLPs. These TEV VLPs elicited broader IgG2-specific antibody response against a novel porcine reproductive and respiratory syndrome virus (PRRSV) protein when compared to the potent IgG1 response induced by the protein alone. Conclusions His-TEV CP was purified by immobilized metal affinity chromatography and assembled into VLPs, some of them reaching 2-μm length. TEV VLPs administered along with PRRSV chimeric protein changed the IgG2/IgG1 ratio against the chimeric protein, suggesting that TEV CP can modulate the immune response against a soluble antigen. Electronic supplementary material The online version of this article (doi:10.1186/s12985-016-0651-y) contains supplementary material, which is available to authorized users.

The present feature describes for the first time the application of spores from Aspergillus sp. IMPMS7 to break out crude oil-in-water emulsions (O/W). The fungal spores were isolated from marine sediments polluted with petroleum hydrocarbons. The spores exhibited the ability to destabilize different O/W emulsions prepared with medium, heavy or extra-heavy Mexican crude oils with specific gravities between 10.1 and 21.2°API. The isolated fungal spores showed a high hydrophobic power of 89.3 ± 1.9% and with 2 g of spores per liter of emulsion, the half-life for emulsion destabilization was roughly 3.5 and 0.7 h for extra-heavy and medium crude oil, respectively. Then, the kinetics of water separation and the breaking of the O/W emulsion prepared with heavy oil through a spectrofluorometric technique were studied. A decrease in the fluorescence ratio at 339 and 326 nm (I339/I326) was observed in emulsions treated with spores, which is similar to previously reported results using chemical demulsifiers.

Semiconductor quantum dots (QDs) have been extensively used for biomedical applications as efficient biomarkers and biosensors. The liposome encapsulation presents an alternative method for quantum dots labeling to facilitate intracellular delivery of the QDs systems. The semiconductor CdSe/ZnS core/shell quantum dots of two different emission wavelengths (530 and 640nm) were encapsulated in liposomes prepared using a new “chemically green“ method: by sonication and freezingunfreezing procedure and without organic solvents application. The QDs-liposomes hybrids were studied by photoluminescence (PL) spectroscopy before and after quantum dots encapsulation. The liposomes encapsulation of both sizes of quantum dots changes of photoluminescence spectra up to higher emission energies. The advantages of CdSe/ZnS core/shell QDs encapsulation on “green” liposomes may be promising in biomedical applications as efficient biomarkers with water dispersability. At the same time, the energy change of QDs emission due to liposome encapsulation may be interesting for biosensoring applications.