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1.
Enzyme Microb Technol ; 151: 109917, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34649688

RESUMO

Lignin is a major byproduct of pulp and paper industries, which is resistant to depolymerization due to its heterogeneous structure. The enzymes peroxidases can be utilized as potent bio-catalysts to degrade lignin. In the current study, an Efeb gene of 1251bp encoding DyP-type peroxidase from Bacillus sp. strain BL5 (DyPBL5) was amplified, cloned into a pET-28a (+) vector and expressed in Escherichia coli BL21 (DE3) cells. A 46 kDa protein of DyPBL5 was purified through ion-exchange chromatography. Purified DyPBL5 was active at wide temperature (25-50 °C) and pH (3.0-8.0) range with optimum activity at 35 °C and pH 5.0. Effects of different chemicals on DyPBL5 were determined. The enzyme activity was strongly inhibited by SDS, DDT and ß-mercaptoethanol, whereas stimulated in the presence of organic solvents such as methanol and ethanol. The kinetic parameters were determined and Km, Vmax and Kcat values were 1.06 mM, 519.75 µmol/min/mg and 395 S̶ 1, respectively. Docking of DyPBL5 with ABTS revealed that, Asn 244, Arg 339, Asp 383 and Thr 389 are putative amino acids, taking part in the oxidation of ABTS. The recombinant DyPBL5 resulted in the reduction of lignin contents up to 26.04 %. The SEM and FT-IR analysis of test samples gave some indications about degradation of lignin by DyPBL5. Various low molecular weight lignin degradation products were detected by analyzing the samples through gas chromatography mass spectrometry. High catalytic efficiency and lignin degradation rate make DyPBL5 an ideal bio-catalyst for remediation of lignin-contaminated sites.

2.
Braz J Biol ; 83: e242536, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495143

RESUMO

Chromium (VI) a highly toxic metal, a major constituent of industrial waste. It is continuously release in soil and water, causes environmental and health related issues, which is increasing public concern in developing countries like Pakistan. The basic aim of this study was isolation and screening of chromium resistant bacteria from industrial waste collected from Korangi and Lyari, Karachi (24˚52'46.0"N 66˚59'25.7"E and 24˚48'37.5"N 67˚06'52.6"E). Among total of 53 isolated strains, seven bacterial strains were selected through selective enrichment and identified on the basis of morphological and biochemical characteristics. These strains were designated as S11, S13, S17, S18, S30, S35 and S48, resistance was determined against varying concentrations of chromium (100-1500 mg/l). Two bacterial strains S35 and S48 showed maximum resistance to chromium (1600 mg/l). Bacterial strains S35 and S48 were identified through 16S rRNA sequence and showed 99% similarity to Bacillus paranthracis and Bacillus paramycoides. Furthermore, growth condition including temperature and pH were optimized for both bacterial strains, showed maximum growth at temperature 30ºC and at optimum pH 7.5 and 6.5 respectively. It is concluded that indigenous bacterial strains isolated from metal contaminated industrial effluent use their innate ability to transform toxic heavy metals to less or nontoxic form and can offer an effective tool for monitoring heavy metal contamination in the environment.


Assuntos
Cromo , Metais Pesados , Bacillus , Bactérias/genética , Biodegradação Ambiental , Resíduos Industriais/análise , RNA Ribossômico 16S/genética
3.
Sci Rep ; 11(1): 18026, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34504138

RESUMO

Salmonella Typhimurium is a human pathogen associated with eggs and egg-derived products. In Australia, it is recommended that eggs should be refrigerated to prevent condensation that can enhance bacterial penetration across the eggshell. Except for the United States, the guidelines on egg refrigeration are not prescriptive. In the current study, in-vitro and in-vivo experiments were conducted to understand the role of egg storage temperatures (refrigerated vs ambient) on bacterial load and the virulence genes expression of Salmonella Typhimurium. The in-vitro egg study showed that the load of Salmonella Typhimurium significantly increased in yolk and albumen stored at 25 °C. The gene expression study showed that ompR, misL, pefA, spvA, shdA, bapA, and csgB were significantly up-regulated in the egg yolk stored at 5 °C and 25 °C for 96 h; however, an in-vivo study revealed that mice infected with egg yolk stored at 25 °C, developed salmonellosis from day 3 post-infection (p.i.). Mice fed with inoculated egg yolk, albumen, or eggshell wash stored at refrigerated temperature did not show signs of salmonellosis during the period of the experiment. Data obtained in this study highlighted the importance of egg refrigeration in terms of improving product safety.

4.
Enzyme Microb Technol ; 148: 109799, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34116753

RESUMO

Most of the presently known ß-glucosidases are sensitive to end-product inhibition by glucose, restricting their potential use in many industrial applications. Identification of novel glucose tolerant ß-glucosidase can prove a pivotal solution to eliminate end-product inhibition and enhance the overall lignocellulosic saccharification process. In this study, a novel gene encoding ß-glucosidase BglNB11 of 1405bp was identified in the genome of Saccharomonospora sp. NB11 and was successfully cloned and heterologously expressed in E. coli BL21 (DE3).The presence of conserved amino acids; NEPW and TENG indicated that BglNB11 belonged to GH1 ß-glucosidases. The recombinant enzyme was purified using a Ni-NTA column, with the molecular mass of 51 kDa, using SDS-PAGE analysis. BglNB11 showed optimum activity at 40 °C and pH 7 and did not require any tested co-factors for activation. The kinetic values, Km, Vmax, kcat, and kcat/Km of purified enzyme were 0.4037 mM, 5735.8 µmol/min/mg, 5042.16 s-1 and 12487.71 s-1 mM-1, respectively. The enzyme was not inhibited by glucose to a concentration of 4 M but was slightly stimulated in the presence of glucose. Molecular docking of BglNB11 with glucose suggested that the relative binding position of glucose in the active site channel might be responsible for modulating end product tolerance and stimulation. ß-glucosidase from BglNB11 is an excellent enzyme with high catalytic efficiency and enhanced glucose tolerance compared to many known glucose tolerant ß-glucosidases. These unique properties of BglNB11 make it a prime candidate to be utilized in many biotechnological applications.


Assuntos
Glucose , beta-Glucosidase , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Especificidade por Substrato , Temperatura , beta-Glucosidase/genética , beta-Glucosidase/metabolismo
5.
Water Sci Technol ; 83(9): 2287-2295, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33989193

RESUMO

The environmental release of mercury is continuously increasing with high degree of mobility, transformation and amplified toxicity. Improving remediation strategies is becoming increasingly important to achieve more stringent environmental safety standards. This study develops a laboratory-scale reactor for bioremediation of aqueous mercury using a biofilm-producing bacterial strain, KBH10, isolated from mercury-polluted soil. The strain was found resistant to 80 mg/L of HgCl2 and identified as Bacillus nealsonii via 16S rRNA gene sequence analysis. The strain KBH10 was characterized for optimum growth parameters and its mercury biotransformation potential was validated through mercuric reductase assay. A packed-bed column bioreactor was designed for biofilm-mediated mercury removal from artificially contaminated water and residual mercury was estimated. Strain KBH10 could grow at a range of temperature (20-50 °C) and pH (6.0-9.0) with optimum temperature established at 30 °C and pH 7.0. The optimum mercuric reductase activity (77.8 ± 1.7 U/mg) was reported at 30 °C and was stable at a temperature range of 20-50 °C. The residual mercury analysis of artificially contaminated water indicated 60.6 ± 1.5% reduction in mercury content within 5 h of exposure. This regenerative process of biofilm-mediated mercury removal in a packed-bed column bioreactor can provide new insight into its potential use in mercury bioremediation.


Assuntos
Mercúrio , Bacillus , Biodegradação Ambiental , Laboratórios , RNA Ribossômico 16S/genética , Água
6.
Food Res Int ; 141: 110117, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33641984

RESUMO

Despite food safety recommendations, raw egg-based foods, such as mayonnaise, are frequently identified as the source of Salmonella during outbreaks. Acidification and storage temperature have been linked with reduced bacterial culturability. Raw egg-based sauces stored at 25 °C have historically been linked with faster decline of Salmonella culturability than preparations stored at 5 °C. This study aimed to determine whether reduced culturability in acidified mayonnaise correlated with reduced in vitro bacterial motility, invasiveness and viability as well as disease-causing capacity in BALB/c mice. Acidification of mayonnaise and incubation at 25 °C for 4 h significantly reduced culturability of Salmonella Typhimurium DT9 but was dependent on initial bacterial load. Bacteria recovered from acidified mayonnaise exhibited reduced invasiveness into polarized cultured intestinal epithelial cells and 12 h post inoculation were no longer invasive suggesting a reduced capacity to cause disease. To confirm this, BALB/c mice were inoculated with Salmonella Typhimurium contaminated mayonnaise stored at 5 °C or 25 °C for 12, 24, 48, 72, and 96 h. Mice inoculated with mayonnaise incubated at 5 °C for 12 and 24 h exhibited mild to moderate disease symptoms; all other mayonnaise treatment groups did not exhibit disease symptoms. In acidified mayonnaise, Salmonella Typhimurium DT9 exhibited a global downregulation of metabolism, stress response, and virulence genes upon addition to mayonnaise. After 4 h of incubation at both 5 °C and 25 °C, however, the vast majority of genes were upregulated which was maintained over the 96-hour experiment suggesting that bacteria were severely stressed. Salmonella Typhimurium DT9 cells were isolated from mayonnaise samples and ATP production was quantified. At both 5 °C and 25 °C, ATP production decreased in acidified mayonnaise preparations. At 25 °C, ATP production decreased more rapidly than at 5 °C. After 24 h, ATP production of bacteria in mayonnaise stored at 25 °C was not significantly different from the dead control group. Thus, the current recommendation of only serving freshly prepared raw egg-sauces or refrigerating immediately after preparation, could be placing consumers at higher risk for contracting salmonellosis.


Assuntos
Salmonella typhimurium , Animais , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos BALB C , Salmonella typhimurium/genética , Temperatura , Virulência
7.
Carbohydr Polym ; 257: 117617, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33541645

RESUMO

Current work focuses on the synthesis and characterization of novel pH-sensitive biocompatible gelatin/carboxymethyl cellulose based hydrogels by free radical polymerization technique cross-linked with glutaraldehyde. Effect of pH, polymer ratio and variable crosslinking concentrations on dynamic swelling, equilibrium swelling, porosity, sol-gel analysis and in vitro release pattern was investigated. Hydrogel structure was confirmed by FTIR, XRD, and DSC. Moreover scanning electron microscopy confirmed the porous structure of gel network. Various structure property relationships like average molecular weight between crosslinks (Mc), solvent interaction parameters, volume fraction of polymer (V2,s) and diffusion coefficient (D) that affect the release behaviour were determined. Results showed that maximum swelling and highest release of drug occurred at pH 1.2. Porosity and gel fraction increased by increasing polymer load. The invivo absorption and pharmacokinetics evaluation in rabbit's models revealed the controlled nature of hydrogels. MTT assay confirmed the biocompatible nature of blank hydrogels against Vero cell lines and cytotoxic potential against HeLa cell lines. The preliminary safety evaluation and oral tolerability revealed that the hydrogel solution is safe up to 4000 mg/kg body weight without causing any hematological or histopathological changes in rabbits.


Assuntos
Carboximetilcelulose Sódica/química , Sistemas de Liberação de Medicamentos , Fluoruracila/química , Gelatina/química , Hidrogéis/química , Animais , Disponibilidade Biológica , Varredura Diferencial de Calorimetria , Bovinos , Chlorocebus aethiops , Reagentes para Ligações Cruzadas/química , Liberação Controlada de Fármacos , Células HeLa , Humanos , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Nanopartículas/química , Polimerização , Polímeros/química , Porosidade , Coelhos , Espectroscopia de Infravermelho com Transformada de Fourier , Sais de Tetrazólio/química , Tiazóis/química , Células Vero , Difração de Raios X
8.
Int Microbiol ; 24(2): 183-196, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33404934

RESUMO

High-altitude cold habitats of the Karakoram are rarely explored for their bacterial community characterization and metabolite productions. In the present study, bacterial communities in ice, water, and sediments of Batura Glacier were investigated using culture-dependent and culture-independent methods. Twenty-seven cold-adapted bacterial strains (mostly psychrotrophic) were isolated using R2A, Tryptic Soy Agar (TSA), and Luria-Bertani (LB) media, at 4 °C and 15 °C. Most of the isolates exhibited growth at a wide range of temperature (4-35 °C), pH (5-12), and salinity (1-6%). Among the bacterial isolates, 52% were identified as Gram-positive and the remaining 48% represented as Gram-negative. The results of phylogenetic analysis indicated that all the culturable bacteria belonged to 3 major phylogenetic groups, i.e., Actinobacteria (48%), Bacteroidetes (26%), and Proteobacteria (22%), while Flavobacterium (26%), Arthrobacter (22%), and Pseudomonas (19%) were represented as the dominant genera. Similarly, Illumina amplicon sequencing of 16S rRNA genes after PCR amplification of DNA from the whole community revealed dominance of the same phylogenetic groups, Proteobacteria, Actinobacteria, and Bacteroidetes, while Arthrobacter, Mycoplana, Ochrobactrum, Kaistobacter, Janthinobacterium, and Flavobacterium were found as the dominant genera. Among the culturable isolates, 70% demonstrated activity for cellulases, 48% lipases, 41% proteases, 41% DNases, and only 7% for amylases. Most of the glacial isolates demonstrated antimicrobial activity against other microorganisms including the multiple-drug-resistant strains of Candida albicans, Klebsiella pneumoniae, Acinetobacter sp., and Bacillus sp. 67% of Gram-negative while 46% of Gram-positive glacial bacteria were resistant to trimethoprim/sulfamethoxazole. Resistance against methicillin and vancomycin among the Gram-positive isolates was 23% and 15%, respectively, while 11% of the Gram-negative isolates exhibited resistance against both colistin sulfate and nalidixic acid.


Assuntos
Bactérias/isolamento & purificação , Camada de Gelo/microbiologia , Microbiota , Antibacterianos/farmacologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , DNA Bacteriano/genética , DNA Ribossômico/genética , Paquistão , Filogenia , RNA Ribossômico 16S/genética
9.
J Biomater Sci Polym Ed ; 32(3): 281-319, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32976729

RESUMO

Curcumin has been reported to be used widely against many types of pathological conditions in clinics. However, due to its limitations such as poor solubility, poor oral absorption and low stability have limited its applications. In the current study, a series of novel chemically cross-linkable depot gel formulations were developed based on thermoresponsive micellar polymer (Pluronic®127) with polyelectrolyte hydrophilic monomer, that is, 2-acrylamido-2-methylpropane sulfonic acid by cold and in situ grafting polymerization method. The formulations were aimed to deliver curcumin at controlled rate from in situ formed depot after administration through subcutaneous route in vivo. The sol-gel phase transitions of formulations were observed by rheological analysis, tube titling and optical transmittance measurements. Maximum swelling of gel formulations was observed at pH 7.4 and below CGT, that is, 25 °C. The in vitro release profile exhibits maximum drug release at pH 7.4 and 25 °C owing to relaxed gel state. In vitro degradation profile of gel formulations showed controlled degradation rate. Cell growth inhibition study confirmed the biocompatibility and safe nature of bare gel formulations against L929 cell lines. In vitro cytotoxic study showed that curcumin loaded in gel formulation has controlled pharmacological activity against HeLa and MCF-7 cancer cells as compared to free drug solution. The IC50 values calculated for pure curcumin solution (30 ± 0.77 µg/ml for HeLa and 27 ± 0.39 µg/ml for MCF-7) were found higher in comparison to curcumin-loaded thermogels against HeLa (19 ± 0.28 µg/ml and 23 ± 0.81 µg/ml) and MCF-7 (22 ± 0.54 µg/ml and 21 ± 0.49 µg/ml). Histopathological and hematological analysis showed the biocompatible nature of hydrogels. Structural confirmation was done by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance spectroscopy (1H NMR). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed the thermal stability of the gel formulation. The porous structure of gel formulations was assessed by scanning electron microscopic (SEM) analysis. Results concluded that newly developed gel formulations have thermoresponsive behavior with phase transition at body temperature and can be used as in situ controlled drug depot.

11.
Digestion ; 102(3): 342-356, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32570246

RESUMO

BACKGROUND: Eosinophilic esophagitis (EoE) is an immune-mediated clinicopathological condition characterized by esophageal infiltration with eosinophils resulting in chronic inflammation and stricture. SUMMARY: The recent increase in the incidence of EoE and the characteristic presentation of symptoms with difficulty swallowing and food bolus impaction has raised key concerns of clinicians as well as researchers. EoE often presents with dysphagia, food impaction, nausea, regurgitation or vomiting, and decreased appetite. It is more common in males, affecting both adults and children. The causative manner of this condition is complex and multifactorial. Throughout recent years, researchers have made a significant contribution to understanding the pathogenesis of EoE, genetic background, natural history, work on allergy, and standardization in the evaluation of disease activity. There is relatively high prevalence of EoE among the population, emphasizing the importance of this disease. Key messages: Esophageal involvement with eosinophils may be manifested as isolated or with coexisting conditions and should be taken into consideration in the differential diagnosis. This study aimed to provide gastroenterologists with novel insights into the evaluation of esophageal involvement with eosinophils and to pay special attention to the etiological factors, coexisting clinical diseases, and complications.

12.
Expert Rev Gastroenterol Hepatol ; 15(3): 255-273, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33121300

RESUMO

INTRODUCTION: Early gastric cancer (EGC) is a well-defined gastric malignancy that is limited to the mucosa or submucosa, irrespective of lymph node metastasis. At an early stage, gastric cancer often does not cause symptoms until it becomes advanced, and it is a heterogeneous disease and usually encountered in its late stages. AREA COVERED: This comprehensive review will provide a novel insight into the evaluation of EGC epidemiology, defining terms, extensive etiology and risk factors, and timely diagnosis since prevention is an essential approach for controlling this cancer and reducing its morbidity and mortality. EXPERT OPINION: The causative manner of EGC is complex and multifactorial. In recent years, researchers have made significant contributions to understanding the etiology and pathogenesis of EGC, and standardization in the evaluation of disease activity. Though the incidence of this cancer is steadily declining in some advanced societies owing to appropriate interventions, there remains a serious threat to health in developing nations. Early detection of resectable gastric cancer is crucial for better patient outcomes.

13.
Life Sci ; 267: 118931, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33359243

RESUMO

AIMS: Aim of the study was to enhance the solubility of Chlorthalidone by developing beta-cyclodextrin cross-linked hydrophilic nanomatrices. MAIN METHODS: Nine different formulations were fabricated by free radical polymerization technique. All formulations were characterized through different studies. FTIR spectroscopy of unloaded and loaded nanomatrices was processed to determine compatibility of constituents and that of the drug with the system. Surface morphology of the nanomatrices was studied by SEM. The size of the optimized formulation was determined by zeta sizer. Swelling, in-vitro release and solubility studies were carried out in different media and results of in-vitro release profiles of nanomatrices and commercially available tablet of Chlorthalidone were compared. For determination of biocompatibility, toxicity studies were proclaimed in rabbits. KEY FINDINGS: Main peaks of corresponding functional groups of individual constituents and that of drug were depicted in FTIR spectra of unloaded and loaded nanomatrices. Porous and fluffy structure was visualized through SEM images. Particle size of the optimized formulation was in the range of 175 ± 5.27 nm. Percent loading of optimized formulation showed the best result. Comparing the in-vitro drug release profiles of nanomatrices and commercially available tablet, the results of the synthesized nanomatrices were quite satisfactory. Solubility profiles were also high as compared to the drug alone. Moreover, toxicity studies confirmed that nanomatrices were biocompatible and no sign of any toxic effect was found. SIGNIFICANCE: We concluded that our developed nanomatrices had successfully enhanced the solubility of Chlorthalidone and can also be used for other poorly aqueous soluble drugs.


Assuntos
Clortalidona/farmacologia , Nanomedicina/métodos , beta-Ciclodextrinas/química , Animais , Varredura Diferencial de Calorimetria , Clortalidona/química , Sistemas de Liberação de Medicamentos/métodos , Liberação Controlada de Fármacos/fisiologia , Masculino , Microscopia Eletrônica de Varredura , Tamanho da Partícula , Porosidade , Coelhos , Solubilidade/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Difração de Raios X
14.
Front Microbiol ; 11: 581201, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33072053

RESUMO

Determining the viable and non-viable load of foodborne pathogens in animal production can be useful in reducing the number of human outbreaks. In this study, we optimized a PMAxxTM-based qPCR for quantifying viable and non-viable load of Salmonella from soil collected from free range poultry environment. The optimized nucleic acid extraction method resulted in a significantly higher (P < 0.05) yield and quality of DNA from the pure culture and Salmonella inoculated soil samples. The optimized primer for the amplification of the invA gene fragment showed high target specificity and a minimum detection limit of 102 viable Salmonella from soil samples. To test the optimized PMAxxTM-based qPCR assay, soil obtained from a free range farm was inoculated with Salmonella Enteritidis or Salmonella Typhimurium, incubated at 5, 25, and 37°C over 6 weeks. The survivability of Salmonella Typhimurium was significantly higher than Salmonella Enteritidis. Both the serovars showed moisture level dependent survivability, which was significantly higher at 5°C compared with 25°C and 37°C. The PMAxxTM-based qPCR was more sensitive in quantifying the viable load compared to the culture method used in the study. Data obtained in the current study demonstrated that the optimized PMAxxTM-based qPCR is a suitable assay for quantification of a viable and non-viable load of Salmonella from poultry environment. The developed assay has applicability in poultry diagnostics for determining the load of important Salmonella serovars containing invA.

15.
Appl Microbiol Biotechnol ; 104(21): 9327-9342, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32960293

RESUMO

Temporal regulation of global gene expression in the caeca of chickens infected with Salmonella Typhimurium has not been investigated previously. In this study, we performed the transcriptome analysis of the caeca of Salmonella Typhimurium challenged chicks to understand the regulation of the mucosal immune system in a temporal manner. The Salmonella infection resulted in the activation of the caecal immune system by the upregulation of the differentially expressed genes (DEGs; false discovery rate (FDR) < 0.05; log2 fold change > 1) involved in biological pathways such as Toll-like receptor signaling pathway, Salmonella infection, cytokine-cytokine receptor interaction, phagosome, apoptosis and intestinal immune network for IgA production. The activation of biological pathways such as RIG-I-like receptor signaling pathway, ErbB signaling pathway and cellular senescence showed a time-dependent response of the host immune system. A 49% increase in the DEGs on day 7 compared with day 3 post-infection (p.i.) suggested a time-dependent role of multiple genes such as AvBD1, AvBD2, AvBD7, IL2, IL10, IL21, SIVA1, CD5, CD14 and GPR142 in the regulation of the immune system. Nested network analysis of the individual biological pathways showed that IL6 played a significant role in the immune system regulation by activating the pathways, including Toll-like receptor signaling pathway, Salmonella infection, intestinal immune network for IgA production and C-type lectin receptor signaling pathway. The downregulated DEGs (FDR < 0.05; log2 fold change < -1) showed that Salmonella challenge affected the functions of pathways, such as tryptophan metabolism, retinol metabolism, folate biosynthesis and pentose and glucoronate interconversions, suggesting the disruption of cellular mechanisms involved in nutrient synthesis, absorption and metabolism. Overall, the immune response was temporally regulated through the activation of Toll-like signaling receptor pathway, cytokine-cytokine interactions and Salmonella infection, where IL6 played a significant role in the modulation of caecal immune system against Salmonella Typhimurium. KEY POINTS: • The immune response to Salmonella Typhimurium challenge was temporally regulated in the caeca of chickens. • Many newly identified genes have been shown to be involved in the activation of the immune system. • Toll-like receptors and interleukins played a key role in immune system regulation.


Assuntos
Galinhas , Salmonella typhimurium , Animais , Ceco , Perfilação da Expressão Gênica , Imunidade nas Mucosas , Salmonella typhimurium/genética , Transcriptoma
16.
Arch Biochem Biophys ; 694: 108543, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32798459

RESUMO

Genomic selection has an essential role in the livestock economy by increasing selection productivity. Genomics provides a mechanism to increase the rate of genetic gain using marker-assisted selection. Various quantitative trait loci (QTL) associated with body, carcass and meat quality traits in beef cattle have been found. It is widely accepted that QTL traits in livestock species are regulated by several genes and factors from the environment. Genome-wide association studies (GWAS) are a powerful approach in identifying QTL and to establish genomic regions harboring the genes and polymorphisms associated with specific characteristics in beef cattle. Due to their impact on economic returns, growth, carcass and meat quality traits of cattle are frequently used as essential criteria in selection in breeding programs., GWAS has been used in beef cattle breeding and genetic program and some progress has been made. Furthermore, numerous genes and markers related to productivity traits in beef cattle have been found. This review summarizes the advances in the use of GWAS in beef cattle production and outlines the associations with growth, carcass, and meat quality.


Assuntos
Pesos e Medidas Corporais , Estudo de Associação Genômica Ampla , Locos de Características Quantitativas , Animais , Bovinos , Qualidade dos Alimentos , Genes , Mutação , Carne Vermelha
17.
Gastroenterol Res Pract ; 2020: 6591341, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32587613

RESUMO

Background: To assess the role of endoscopic ultrasound (EUS) in the diagnosis of upper gastrointestinal subepithelial lesions (SELs) and to investigate EUS combined with a grayscale histogram analysis for the differentiation of leiomyomas and gastrointestinal stromal tumors (GISTs). Methods: A retrospective study of 709 patients with upper gastrointestinal SELs was conducted by EUS before endoscopic resection. The EUS findings of SELs and pathological results after endoscopic resection were compared. The EUS images of SELs, particularly, leiomyoma and GIST, were further analyzed via a grayscale histogram to differentiate between the two tumors. Results: Of the 709 patients, 47 cases were pathologically undetermined. The diagnostic consistency of EUS with endoscopic resection was 88.2% (584/662), including 185 muscularis mucosa, 61 submucosa, and 338 muscularis propria, respectively. The diagnostic consistency of EUS with pathology was 80.1% (530/662). The gray value of GISTs was significantly higher than that of leiomyomas (58.9 ± 8.3 vs. 39.5 ± 5.9, t = 57.0, P < 0.0001). The standard deviation of leiomyomas was significantly lower than that of GISTs (20.6 ± 7.0 vs. 39.8 ± 9.3, t = 23.7, P < 0.0001). The grayscale histogram analysis of GISTs showed higher echo ultrasound, and the echo of leiomyoma was more uniform. Conclusion: EUS is the preferred procedure for the evaluation of upper gastrointestinal SELs. EUS combined with a grayscale histogram analysis is an effective method for the differentiation of leiomyomas and GISTs.

18.
J Basic Microbiol ; 60(7): 600-612, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32363591

RESUMO

Industrial applications require enzymes to be highly stable and economically viable in terms of reusability. Enzyme immobilization is an exciting alternative to improve the stability of enzymatic processes. Immobilization of ß-1,4-xylanase produced by Bacillus licheniformis S3 is performed by using two polymer supports (agar-agar and calcium alginate). The maximum enzyme immobilization yield was achieved at a concentration of 3% agar, whereas a combination of sodium alginate, 4%, and calcium chloride, 0.3 M, was used for the formation of immobilized beads. The immobilization process increased the optimum reaction time from 10 min to 35 and 40 min for agar and calcium alginate, respectively, and the incubation temperature increased from 55°C to 60°C for agar, but it remained unchanged for calcium alginate. The pH profile of free and immobilized xylanase was quite similar in both cases. Both the techniques altered the kinetic parameters of immobilized ß-1,4-xylanase as compared with the free enzyme. The diffusion limit of high molecular weight xylan caused a decline in Vmax of the immobilized enzyme, whereas there was an increase in the Km value. However, calcium alginate-immobilized enzyme displayed broad thermal stability as compared with agar-agar-immobilized enzyme and retained 57.1% of its initial activity at 80°C up to 150 min. Biotechnological characterization showed that the reusability of enzymes was the most striking finding, particularly of immobilized xylanase using agar-agar as immobilization carrier, which after six cycles retained 23% activity.


Assuntos
Bacillus licheniformis/metabolismo , Endo-1,4-beta-Xilanases/metabolismo , Enzimas Imobilizadas/metabolismo , Xilanos/metabolismo , Ágar/química , Alginatos/química , Enzimas Imobilizadas/química
19.
Appl Environ Microbiol ; 86(13)2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32332137

RESUMO

The microbiota plays a vital role in maintaining gut health and influences the overall performance of chickens. Most gut microbiota-related studies have been performed in broilers, which have different microbial communities compared to those of layers. The normal gut microbiota of laying chickens is dominated by Proteobacteria, Firmicutes, Bacteroidetes, Fusobacteria, and Actinobacteria at the phylum level. The composition of the gut microbiota changes with chicken age, genotype, and production system. The metabolites of gut microbiota, such as short-chain fatty acids, indole, tryptamine, vitamins, and bacteriocins, are involved in host-microbiota cross talk, maintenance of barrier function, and immune homeostasis. Resident gut microbiota members also limit and control the colonization of foodborne pathogens. In-feed supplementations of prebiotics and probiotics strengthen the gut microbiota for improved host performance and colonization resistance to gut pathogens, such as Salmonella and Campylobacter The mechanisms of action of prebiotics and probiotics come through the production of organic acids, activation of the host immune system, and production of antimicrobial agents. Probiotic candidates, including Lactobacillus, Bifidobacterium, Bacillus, Saccharomyces, and Faecalibacterium isolates, have shown promising results toward enhancing food safety and gut health. Additionally, a range of complex carbohydrates, including mannose oligosaccharides, fructo-oligosaccharides, and galacto-oligosaccharides, and inulin are promising candidates for improving gut health. Here, we review the potential roles of prebiotics and probiotics in the reshaping of the gut microbiota of layer chickens to enhance gut health and food safety.


Assuntos
Galinhas/microbiologia , Inocuidade dos Alimentos , Microbioma Gastrointestinal/efeitos dos fármacos , Prebióticos/administração & dosagem , Probióticos/administração & dosagem , Animais , Feminino
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