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3.
Sci Total Environ ; 760: 143390, 2021 Mar 15.
Article in English | MEDLINE | ID: mdl-33213909

ABSTRACT

This study presents for the first time results about the microplastic concentration and their origin in a stream of the Pampas region in Argentina, receiving wastewater of an intermediate city. The most appropriate procedure to analyze and quantify the microplastics in the studied system is the use of an oxidative digestion process using a 30% H2O2 solution to eliminate the organic matter in the samples. A high quantity of MPs, on the order of millions of microplastics per m3 of water, was estimated in the Langueyú stream. 56% of the microplastics correspond to fibers with diameters between 10 and 15 µm and lengths less than 500 µm, while 44% are fragments with sizes of tens of micrometers. Raman microspectroscopy was used to identify the type of fibers. The characteristics of the microplastic fibers released in a wash load test are comparable with those observed in the Langueyú stream, in particular, the average sizes and the distribution of the diameters of the MPFs are similar. The processes in the sewage treatment plant, prior to their discharge in the stream, would affect the color of the fibers and their length.

4.
Medicina (B.Aires) ; 80(3): 289-291, jun. 2020. graf, tab
Article in Spanish | LILACS | ID: biblio-1125082

ABSTRACT

El hipoparatiroidismo (hipoPTH) es una enfermedad infrecuente caracterizada por hipocalcemia y niveles inapropiadamente bajos o ausentes de parathormona. Presentamos el caso de un hombre de 25 años, deportista de alto rendimiento, con antecedente de hipoPTH secundario a tiroidectomía total dos años antes por cáncer papilar multifocal bilateral tiroideo, estadificado como T3 N1b M0, derivado por hipocalcemia sintomática. Presentaba calcemias promedio de 7mg%, síntomas de hipocalcemia en reposo y múltiples internaciones. Inicialmente, se optimizó tratamiento convencional con aporte de calcio vía oral hasta 12g/día, vitamina D y calcitriol, sin mejoría clínica ni bioquímica. Se descartaron malabsorción y complicaciones crónicas de hipoPTH. Se evidenció a través de cuestionario de salud SF-36 disminución de la calidad de vida. Se indicó sustitución con parathormona recombinante humana [rhPTH(1-84)] 50μg/día subcutánea con posterior ascenso a 75μg y reducción progresiva de la medicación por vía oral. Actualmente se encuentra asintomático, sin requerimiento de calcio ni vitamina D, mantiene calcemias de 9mg%, realiza actividad deportiva y demuestra marcada mejoría en la calidad de vida según cuestionario SF-36 (36-Item Short Form Health Survey).


Hypoparathyroidism (HypoPT) is a rare disease characterized by low calcium and inappropriately low circulating parathormone levels. We present the case of a 25-year-old high-performance athlete male, with history of HypoPT after total thyroidectomy for papillary thyroid carcinoma (T3 N1b M0) two years before, who was referred to our clinic for symptomatic hypocalcemia. The patient reported serum calcium average levels of 7mg%, presented symptoms of hypocalcemia at rest and had multiple hospital admissions. First, standard treatment was optimized by calcium supplementation up to 12g/d and active vitamin D, not showing clinical or biochemical improvement. Malabsorption and complications of chronic HypoPT were ruled out. The 36-Item Short Form Health Survey (SF-36) demonstrated an impaired quality of life (QoL). Full-length recombinant human parathyroid hormone [rhPTH(1-84)] therapy was started with 50μg/d subcutaneous, and later adjusted to 75μg/d and the oral treatment gradually decreased. Currently, he is asymptomatic, with serum calcium levels above 9mg%, without receiving oral medication. He performs sports activity and shows marked improvement in quality of life according to SF-36 questionnaire.


Subject(s)
Humans , Male , Adult , Parathyroid Hormone/therapeutic use , Hypoparathyroidism/drug therapy , Thyroidectomy/adverse effects , Vitamin D/therapeutic use , Calcitriol/therapeutic use , Thyroid Neoplasms/surgery , Thyroid Neoplasms/complications , Hormone Replacement Therapy/methods , Calcium-Regulating Hormones and Agents/therapeutic use , Thyroid Cancer, Papillary/surgery , Thyroid Cancer, Papillary/complications , Hypoparathyroidism/etiology
5.
Medicina (B Aires) ; 80(3): 289-291, 2020.
Article in Spanish | MEDLINE | ID: mdl-32442945

ABSTRACT

Hypoparathyroidism (HypoPT) is a rare disease characterized by low calcium and inappropriately low circulating parathormone levels. We present the case of a 25-year-old high-performance athlete male, with history of HypoPT after total thyroidectomy for papillary thyroid carcinoma (T3 N1b M0) two years before, who was referred to our clinic for symptomatic hypocalcemia. The patient reported serum calcium average levels of 7mg%, presented symptoms of hypocalcemia at rest and had multiple hospital admissions. First, standard treatment was optimized by calcium supplementation up to 12g/d and active vitamin D, not showing clinical or biochemical improvement. Malabsorption and complications of chronic HypoPT were ruled out. The 36-Item Short Form Health Survey (SF-36) demonstrated an impaired quality of life (QoL). Full-length recombinant human parathyroid hormone [rhPTH(1-84)] therapy was started with 50υg/d subcutaneous, and later adjusted to 75υg/d and the oral treatment gradually decreased. Currently, he is asymptomatic, with serum calcium levels above 9mg%, without receiving oral medication. He performs sports activity and shows marked improvement in quality of life according to SF-36 questionnaire.


El hipoparatiroidismo (hipoPTH) es una enfermedad infrecuente caracterizada por hipocalcemia y niveles inapropiadamente bajos o ausentes de parathormona. Presentamos el caso de un hombre de 25 años, deportista de alto rendimiento, con antecedente de hipoPTH secundario a tiroidectomía total dos años antes por cáncer papilar multifocal bilateral tiroideo, estadificado como T3 N1b M0, derivado por hipocalcemia sintomática. Presentaba calcemias promedio de 7mg%, síntomas de hipocalcemia en reposo y múltiples internaciones. Inicialmente, se optimizó tratamiento convencional con aporte de calcio vía oral hasta 12g/día, vitamina D y calcitriol, sin mejoría clínica ni bioquímica. Se descartaron malabsorción y complicaciones crónicas de hipoPTH. Se evidenció a través de cuestionario de salud SF-36 disminución de la calidad de vida. Se indicó sustitución con parathormona recombinante humana [rhPTH(1-84)] 50υg/día subcutánea con posterior ascenso a 75υg y reducción progresiva de la medicación por vía oral. Actualmente se encuentra asintomático, sin requerimiento de calcio ni vitamina D, mantiene calcemias de 9mg%, realiza actividad deportiva y demuestra marcada mejoría en la calidad de vida según cuestionario SF-36 (36-Item Short Form Health Survey).


Subject(s)
Hypoparathyroidism/drug therapy , Parathyroid Hormone/therapeutic use , Adult , Calcitriol/therapeutic use , Calcium-Regulating Hormones and Agents/therapeutic use , Hormone Replacement Therapy/methods , Humans , Hypoparathyroidism/etiology , Male , Thyroid Cancer, Papillary/complications , Thyroid Cancer, Papillary/surgery , Thyroid Neoplasms/complications , Thyroid Neoplasms/surgery , Thyroidectomy/adverse effects , Vitamin D/therapeutic use
6.
Toxicon ; 180: 43-48, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32298663

ABSTRACT

Zearalenone, an oestogenic mycotoxin produced by Fusarium sp., occurs naturally in agricultural commodities. Economic losses and health concerns associated to mycotoxins has attracted research interest towards exploring novel approaches to detoxify mycotoxin-contaminated food and feed. The aim of the present work was to study the ability of 11 aflatoxin-degrading Bacillus strains to degrade ZEA. In addition, a qualitative assessment of protease, amylase and cellulase activity of the studied Bacillus strains was made. All strains were able to degrade 58-96.9% ZEA after 72 h. Toxicity towards Artemia salina was significantly reduced (P < 0.0001). Degradation extracts fluorescence decreased 50% indicating a probable cleavage of the lactone ring. Strains RC1A, RC3A and RC6A showed a remarkable enzymatic activity, showing potential to be used as feed additives.


Subject(s)
Aflatoxins/metabolism , Amylases/metabolism , Bacillus/metabolism , Cellulases/metabolism , Peptide Hydrolases/metabolism , Zearalenone/metabolism , Agriculture , Inactivation, Metabolic
7.
Toxicon ; 172: 1-7, 2019 Oct 25.
Article in English | MEDLINE | ID: mdl-31610179

ABSTRACT

The presence of contaminants such as aflatoxins (AFs) in dairy products constitutes a serious risk to the health of consumers, especially children who are most sensitive to the adverse effects of AFs. The presence of Aflatoxin M1 (AFM1) in milk is a public health problem since dairy products are massively consumed worldwide. The aim of the present work was to select microorganisms capable of reducing AFM1 entry into the food chain through adsorption/degradation strategies. Moreover, the toxicity of AFM1 degradation products was evaluated. All tested strains had the capacity to adsorb 19%-61% AFM1 in milk. These strains also had the ability to degrade AFM1 into metabolites less toxic than the original toxin. Moreover, this is the first study to report harmless and probiotic Pediococcus pentosaceus and Kluveromyces marxianus have the ability to adsorb and degrade AFM1 to less toxic metabolites in milk.


Subject(s)
Aflatoxin M1/metabolism , Inactivation, Metabolic , Milk/microbiology , Probiotics/pharmacology , Adsorption , Aflatoxin M1/toxicity , Animals , Artemia/drug effects , Food Contamination , Kluyveromyces/metabolism , Pediococcus pentosaceus/metabolism
8.
Food Chem Toxicol ; 124: 316-323, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30557671

ABSTRACT

Microbial degradation of aflatoxins (AFs) is an alternative to the use of mycotoxin binders. The lactone ring is a possible target for microbial enzymes and its cleavage reduces AFs toxicity. The aim of this study was to isolate and identify Bacillus strains able to degrade AFB1 to less toxic metabolites and to identify aiiA genes encoding for N-acyl-homoserine lactone (AHL) lactonase to possibly correlate detoxification with the production of this enzyme. Eleven soilborne Bacillus strains were isolated and identified by MALDI-TOF MS. Ten cultures and eight cell free culture supernatants (CFCS) were able to significantly (P < 0.05) degrade 27.78-79.78% AFB1. Cell lysates were also able to degrade AFB1 (P < 0.05). Exposure to 70 and 80 °C did not affect enzyme activity. Aflatoxin B1 toxicity towards Artemia salina was reduced after degradation by each of the Bacillus strains. B. subtilis RC1B, B. cereus RC1C and B. mojavensis RC3B, amplified a fragment of 753 pb corresponding to the aiiA gene encoding for AHL lactonase. AFB1 degradation by the strains tested was due to the extracellular and intracellular enzymes. If demonstrated to be safe, these could be used to detoxify AFB1 in contaminated food or feed.


Subject(s)
Aflatoxin B1/metabolism , Bacillus/metabolism , Carboxylic Ester Hydrolases/metabolism , Aflatoxin B1/chemistry , Aflatoxin B1/toxicity , Animals , Artemia/drug effects , Bacillus/classification , Bacillus/enzymology , Bacillus/genetics , Carboxylic Ester Hydrolases/genetics , Hydrolysis , Temperature
9.
Carbohydr Polym ; 202: 409-417, 2018 Dec 15.
Article in English | MEDLINE | ID: mdl-30287017

ABSTRACT

The study examines the use of macrobeads for the controlled-release of bacteria. Macrobeads were prepared by an easy dripping-technique using 20/80 wt/wt chitosan-starch blends and sodium tripolyphosphate as cross-linking agent. The resulting polymeric matrix was examined by SEM, XRD, TGA, and solid-RMN. The swelling-equilibrium, thermal behaviour, crystallinity, and size of macrobeads were affected by the autoclave-sterilization. The diameter of the sterilized xerogel was c.a. 1.6 mm. The results suggested that ionotropic-gelation and neutralization were the mechanisms underlying hydrogel formation. Plant growth-promoting bacteria (PGPB) were loaded into macrobeads separately or co-inoculated. Bacteria loaded macrobeads were dried and stored. Bacteria survived at least 12 months in orders of 109 CFU of A. brasilense/g and 108 CFU of P. fluorescens/g. Bacterial release in sterile saline solution tended to a super Case-II transport mechanism. Polymeric-matrix release efficiently both PGPB in natural soils, which uncovers their potential for the formulation of novel and improved biofertilizers.


Subject(s)
Azospirillum brasilense/drug effects , Chitosan/pharmacology , Crops, Agricultural/growth & development , Drug Delivery Systems , Hydrogel, Polyethylene Glycol Dimethacrylate/pharmacology , Pseudomonas fluorescens/drug effects , Starch/pharmacology , Azospirillum brasilense/metabolism , Chitosan/chemistry , Crops, Agricultural/microbiology , Hydrogel, Polyethylene Glycol Dimethacrylate/chemistry , Particle Size , Pseudomonas fluorescens/metabolism , Starch/chemistry
10.
Curr Opin Microbiol ; 37: R1, 2017 06.
Article in English | MEDLINE | ID: mdl-29096911

ABSTRACT

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article that has already been published in , http://dx.doi.org/10.1016/j.mib.2017.03.015 has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error.

11.
Curr Opin Microbiol ; 37: 161-165, 2017 Jun.
Article in English | MEDLINE | ID: mdl-28965021

ABSTRACT

Fungi are organisms with important roles in ecosystem functioning and services, but knowledge about how habitat fragmentation affect fungal diversity is biased by experimental approaches and it is spread in different trophic groups. We analyzed the empirical evidences of fungal diversity in fragmented landscapes, and proposed future perspectives for the study of these organisms under land use changes. Fungal diversity might be negatively affected by habitat fragmentation; however, this trend may differ in magnitude depending on fungal groups and their nutritional habits. In addition, due to the fact that fungal diversity at fragmented landscapes has been studied mainly through few indicators (e.g. isolation, area and edge effect); we propose incorporating the landscape structure and accurate spatio-temporal scales to the study of fungal diversity responses to fragmented landscapes. Together, this methodological refinement may allow improving knowledge on fungi when designing proper strategies for landscape management.


Subject(s)
Biodiversity , Environmental Microbiology , Fungi/classification , Ecosystem , Microbiological Techniques , Spatio-Temporal Analysis
12.
Mycotoxin Res ; 33(4): 273-283, 2017 Nov.
Article in English | MEDLINE | ID: mdl-28687999

ABSTRACT

The aim of this study was to evaluate the efficacy of autochthonous Pichia kudriavzevii as a novel bioadsorbent for aflatoxin B1 (AFB1). The selection of this yeast was based on the AFB1 adsorption capacity previously demonstrated in vitro (Magnoli et al. 2016). One-day-old Cobb broilers (n = 160) were randomly assigned to four dietary treatments (T1: basal diet (B); T2: B + 0.1% yeast; T3: B + AFB1, 100 µg/kg; T4: B + 0.1% yeast + AFB1, 100 µg/kg). Performance parameters (average daily weight gain body, average daily consumption, feed conversion ratio, carcass weight, and dead weight), biochemical parameters (albumin, globulin, and albumin/globulin), liver pathological changes, and AFB1 residual levels in the liver and excreta were evaluated. Significant differences (P < 0.05) in performance parameters were observed among treatments and controls: T3 group showed the lowest average daily body weight gain value while in T4 group, the value of this parameter increased significantly (P < 0.05). T3 and T4 groups showed the lowest and highest values for average daily feed consumption, respectively. The feed conversion ratio (FC) showed no significant differences among treatments. T3 group showed the lowest dead weight and carcass weight compared with T1 group. The biochemical parameters showed no significant differences among treatments. T3 group showed macroscopic and microscopic liver changes compared to the control. Aflatoxin B1 levels (µg/g) were detected in broiler livers and showed significant differences among treatments (P < 0.05). In conclusion, native P. kudriavzevii incorporation (0.1%) in broiler diets containing AFB1 was shown to be effective in ameliorating the adverse effects of AFB1 on production.


Subject(s)
Aflatoxin B1/adverse effects , Chickens , Dietary Supplements , Pichia , Poultry Diseases/prevention & control , Animal Feed/analysis , Animals , Diet/veterinary , Liver/metabolism , Male , Poultry Diseases/pathology , Random Allocation
13.
Curr Opin Microbiol ; 37: 61-66, 2017 06.
Article in English | MEDLINE | ID: mdl-28578292

ABSTRACT

This article that has already been published in , 10.1016/j.mib.2017.03.015 has been withdrawn at the request of the editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. This error bears no reflection on the article or its authors. The publisher apologizes to the authors and the readers for this unfortunate error". The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.

14.
Oncogene ; 35(48): 6189-6202, 2016 12 01.
Article in English | MEDLINE | ID: mdl-27157613

ABSTRACT

ErbB-2 amplification/overexpression accounts for an aggressive breast cancer (BC) subtype (ErbB-2-positive). Enhanced ErbB-2 expression was also found in gastric cancer (GC) and has been correlated with poor clinical outcome. The ErbB-2-targeted therapies trastuzumab (TZ), a monoclonal antibody, and lapatinib, a tyrosine kinase inhibitor, have proved highly beneficial. However, resistance to such therapies remains a major clinical challenge. We here revealed a novel mechanism underlying the antiproliferative effects of both agents in ErbB-2-positive BC and GC. TZ and lapatinib ability to block extracellular signal-regulated kinases 1/2 and phosphatidylinositol-3 kinase (PI3K)/AKT in sensitive cells inhibits c-Myc activation, which results in upregulation of miR-16. Forced expression of miR-16 inhibited in vitro proliferation in BC and GC cells, both sensitive and resistant to TZ and lapatinib, as well as in a preclinical BC model resistant to these agents. This reveals miR-16 role as tumor suppressor in ErbB-2-positive BC and GC. Using genome-wide expression studies and miRNA target prediction algorithms, we identified cyclin J and far upstream element-binding protein 1 (FUBP1) as novel miR-16 targets, which mediate miR-16 antiproliferative effects. Supporting the clinical relevance of our results, we found that high levels of miR-16 and low or null FUBP1 expression correlate with TZ response in ErbB-2-positive primary BCs. These findings highlight a potential role of miR-16 and FUBP1 as biomarkers of sensitivity to TZ therapy. Furthermore, we revealed miR-16 as an innovative therapeutic agent for TZ- and lapatinib-resistant ErbB-2-positive BC and GC.


Subject(s)
Breast Neoplasms/genetics , Cyclins/genetics , DNA Helicases/genetics , DNA-Binding Proteins/genetics , Gene Expression Regulation, Neoplastic/drug effects , MicroRNAs/genetics , Quinazolines/pharmacology , Stomach Neoplasms/genetics , Trastuzumab/pharmacology , 3' Untranslated Regions , Animals , Antineoplastic Agents/pharmacology , Binding Sites , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cell Line, Tumor , Cell Proliferation , Disease Models, Animal , Drug Resistance, Neoplasm/genetics , Female , Genes, Tumor Suppressor , Humans , Lapatinib , Male , Mice , Models, Biological , Promoter Regions, Genetic , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-myc/metabolism , RNA Interference , RNA-Binding Proteins , Receptor, ErbB-2/antagonists & inhibitors , Receptor, ErbB-2/metabolism , Stomach Neoplasms/drug therapy , Stomach Neoplasms/metabolism
15.
Environ Technol ; 37(15): 1923-32, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26732367

ABSTRACT

The Duplex-constructed wetland (CW) is a hybrid system composed of a vertical flow (VF) CW on top of a horizontal flow filter (HFF). Each compartment is designed to play a different role: aerobic treatment in the VF CW due to intermittent feeding and anoxic treatment in the HFF due to saturated conditions. Three Duplex-CWs were used in this study: Control, Aerated and Recirculating. The role of each compartment was tested for pollutant removal and micro-invertebrate abundance. In all systems, the VF CW removed mainly organic matter, solids and NH4(+)-N. Pathogens were removed in both compartments. Likewise, total nitrogen removal occurred in both compartments, only the Recirculating HFF was not able to denitrify the nitrogen due to the slightly more oxic conditions as compared to the other systems. All systems met discharge guidelines for organic matter, but only the Control and Aerated systems met those for total nitrogen. At the applied loading rates, the pollutant removal was not significantly enhanced by the use of aeration and recirculation. Therefore, operation as in the Control system, without aeration or recirculation, is recommended for the tested Duplex-CWs. If artificial aeration will be used in CWs, the support material should be carefully selected to allow a proper air distribution.


Subject(s)
Biodegradation, Environmental , Waste Disposal, Fluid/instrumentation , Wastewater/chemistry , Wetlands , Air , Equipment Design , Silicon Dioxide
16.
Oncogene ; 35(17): 2208-22, 2016 04 28.
Article in English | MEDLINE | ID: mdl-26212010

ABSTRACT

Membrane overexpression of the receptor tyrosine kinase ErbB-2 (MErbB-2) accounts for a clinically aggressive breast cancer (BC) subtype (ErbB-2-positive) with increased incidence of metastases. We and others demonstrated that nuclear ErbB-2 (NErbB-2) also plays a key role in BC and is a poor prognostic factor in ErbB-2-positive tumors. The signal transducer and activator of transcription 3 (Stat3), another player in BC, has been recognized as a downstream mediator of MErbB-2 action in BC metastasis. Here, we revealed an unanticipated novel direction of the ErbB-2 and Stat3 interaction underlying BC metastasis. We found that Stat3 binds to its response elements (GAS) at the ErbB-2 promoter to upregulate ErbB-2 transcription in metastatic, ErbB-2-positive BC. We validated these results in several BC subtypes displaying metastatic and non-metastatic ability, highlighting Stat3 general role as upstream regulator of ErbB-2 expression in BC. Moreover, we showed that Stat3 co-opts NErbB-2 function by recruiting ErbB-2 as its coactivator at the GAS sites in the promoter of microRNA-21 (miR-21), a metastasis-promoting microRNA (miRNA). Using an ErbB-2 nuclear localization domain mutant and a constitutively activated ErbB-2 variant, we found that NErbB-2 role as a Stat3 coactivator and also its direct role as transcription factor upregulate miR-21 in BC. This reveals a novel function of NErbB-2 as a regulator of miRNAs expression. Increased levels of miR-21, in turn, downregulate the expression of the metastasis-suppressor protein programmed cell death 4 (PDCD4), a validated miR-21 target. Using an in vivo model of metastatic ErbB-2-postive BC, in which we silenced Stat3 and reconstituted ErbB-2 or miR-21 expression, we showed that both are downstream mediators of Stat3-driven metastasis. Supporting the clinical relevance of our results, we found an inverse correlation between ErbB-2/Stat3 nuclear co-expression and PDCD4 expression in ErbB-2-positive primary invasive BCs. Our findings identify Stat3 and NErbB-2 as novel therapeutic targets to inhibit ErbB-2-positive BC metastasis.


Subject(s)
Apoptosis Regulatory Proteins/biosynthesis , Breast Neoplasms/genetics , MicroRNAs/biosynthesis , RNA-Binding Proteins/biosynthesis , Receptor, ErbB-2/biosynthesis , STAT3 Transcription Factor/genetics , Adolescent , Adult , Aged , Apoptosis Regulatory Proteins/genetics , Breast Neoplasms/pathology , Cell Line, Tumor , Female , Gene Expression Regulation, Neoplastic , Humans , MicroRNAs/genetics , Middle Aged , Neoplasm Metastasis , RNA-Binding Proteins/genetics , Receptor, ErbB-2/genetics , Signal Transduction , Transcriptional Activation/genetics , Transfection
17.
Mycotoxin Res ; 31(3): 145-50, 2015 Aug.
Article in English | MEDLINE | ID: mdl-25982450

ABSTRACT

In this study, gliotoxin production by Aspergillus fumigatus strains from animal environment is studied. Moreover, a rapid, easy and environment-friendly micro-analytical sample treatment procedure coupled with LC-MS/MS was applied for the determination of gliotoxin from A. fumigatus cultures. The ability of gliotoxin production by 143 strains was assayed in yeast extract sucrose agar, and 1 ml of chloroform was used for toxin extraction without further clean-up. Mean recoveries at two spiking levels (2500 and 7000 ng/g; n = 6) were 100.3 ± 6.6 % relative SD (RSD) and 92.4 ± 3.8 % RSD. Repeatability and within-laboratory reproducibility for different concentration levels of gliotoxin (25 to 1000 ng/ml; n = 12) ranged from 0.3 to 5.4 % RSD and from 3.9 to 12.7 % RSD, respectively. The detection limit of the analytical method was 3.5 ng/g. The ability for gliotoxin production by A. fumigatus revealed that 61.5 % of the strains were able to produce the toxin at levels ranging from LOQ to 3430.5 ng/g. However, all the tested samples had similar percentages of producing strains (81.8 to 86.6 %). The micro-analytical sample treatment coupled with LC-MS/MS detection is a precise and useful methodology for determining gliotoxin from fungal extracts of A. fumigatus and allows working both fast and safely and also reducing the effect on the environment. This toxin plays a critical role in the pathobiology of A. fumigatus, and its presence in animal environments could affect animal health and productivity; in addition, there are risks of contamination for rural workers during handling and storage of animal feedstuffs.


Subject(s)
Aspergillus fumigatus/metabolism , Food Contamination/analysis , Gliotoxin/analysis , Silage/microbiology , Animals , Chromatography, High Pressure Liquid , Gliotoxin/metabolism , Reproducibility of Results , Tandem Mass Spectrometry
18.
J Basic Microbiol ; 54(12): 1310-21, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25138314

ABSTRACT

Azospirillum is a plant growth-promoting rhizobacteria (PGPR) genus vastly studied and utilized as agriculture inoculants. Isolation of new strains under different environmental conditions allows the access to the genetic diversity and improves the success of inoculation procedures. Historically, the isolation of this genus has been performed by the use of some traditional culture media. In this work we characterized the physiology and biochemistry of five different A. brasilense strains, commonly used as cereal inoculants. The aim of this work is to contribute to pose into revision some concepts concerning the most used protocols to isolate and characterize this bacterium. We characterized their growth in different traditional and non-traditional culture media, evaluated some PGPR mechanisms and characterized their profiles of fatty acid methyl esters and carbon-source utilization. This work shows, for the first time, differences in both profiles, and ACC deaminase activity of A. brasilense strains. Also, we show unexpected results obtained in some of the evaluated culture media. Results obtained here and an exhaustive knowledge revision revealed that it is not appropriate to conclude about bacterial species without analyzing several strains. Also, it is necessary to continue developing studies and laboratory techniques to improve the isolation and characterization protocols.


Subject(s)
Azospirillum brasilense/physiology , Soil Microbiology , Azospirillum brasilense/isolation & purification , Carbon/metabolism , Carbon-Carbon Lyases/metabolism , Crops, Agricultural/growth & development , Crops, Agricultural/microbiology , Fatty Acids/metabolism , Indoles/metabolism , Phosphates/metabolism , Siderophores/biosynthesis
19.
Environ Technol ; 35(13-16): 2086-94, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24956803

ABSTRACT

The large area demand of constructed wetlands (CWs) is documented as a weak point that can be potentially reduced by applying active aeration. The aim of this study was, therefore, to understand the effects of aeration on the treatment performance, the biofilm activity, the protozoan population size and potential CW footprint reduction of different horizontal flow (HF) CW configurations. Two experimental periods were considered: a first period with low organic loading rate (OLR) and a second period with high OLR. Three HF CW configurations were compared: a conventional (control), an aerated and a hybrid CW (aerated followed by a non-aerated CW). The results obtained reinforced the competence of aerated CW for organic matter removal (81-89% of chemical oxygen demand) while for nitrogen elimination the control (19-24%) and hybrid (8-41%) systems performed better than the aerated system (-6% to 33%). Biofilm activity and protozoa abundance were distinctly higher at the inlet zones when compared with the outlet zones of all CWs, as well as in the aerated systems when compared with the non-aerated CWs. The protozoan abundance increased with an increase in the OLR and ciliates were found to be the dominant group. Overall, the active aeration highlighted the efficiency and stability of the CWs for organic matter removal and thus can be used as a promising tool to enhance microbial activity and grazing by protozoa; eventually reducing solid accumulation in the bed media. These beneficial effects contribute to reduce the CWs' area requirements.


Subject(s)
Water Microbiology , Water Purification , Wetlands , Aerobiosis , Biofilms , Wastewater/chemistry , Wastewater/microbiology
20.
Fish Shellfish Immunol ; 39(2): 450-7, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24929243

ABSTRACT

Lectins participate in the immune mechanisms of crustaceans. They have been considered as humoral receptors for pathogen-associated molecular patterns; however, some reports suggest that lectins could regulate crustacean cellular functions. In the present study, we purified and characterized a serum lectin (CqL) from the hemolymph of Cherax quadricarinatus by affinity chromatography and determined its participation in the regulation of hemocytes' oxidative burst. CqL is a 290-kDa lectin in native form, constituted by 108, 80, and 29-kDa subunits. It is mainly composed of glycine, alanine, and a minor proportion of methionine and histidine. It showed no carbohydrates in its structure. CqL is composed of several isoforms, as determined by 2D-electrophoresis, and shows no homology with any crustacean protein as determined by Lc/Ms mass spectrometry. CqL agglutinated mainly rat and rabbit erythrocytes and showed a broad specificity for monosaccharides such as galactose, glucose, and sialic acid, as well as for glycoproteins, such as porcine stomach and bovine submaxillary mucin and fetuin. It is a Mn(2+)-dependent lectin. CqL recognized 8% of crayfish granular hemocytes and increased 4.2-fold the production of hemocytes' superoxide anion in vitro assays when compared with non-treated hemocytes. This effect showed the same specificity for carbohydrates as hemagglutination; moreover, superoxide dismutase and diphenyleneiodonium chloride were effective inhibitors of CqL oxidative-activation. The CqL homoreceptor is a 120-kDa glycoprotein identified in the hemocytes lysate. Our results suggest that CqL participates actively in the regulation of the generation of superoxide anions in hemocytes using NADPH-dependent mechanisms.


Subject(s)
Astacoidea/chemistry , Astacoidea/immunology , Hemocytes/immunology , Lectins/analysis , Agglutination Tests , Amino Acids/analysis , Animals , Blotting, Western , Chromatography, Affinity , Electrophoresis, Gel, Two-Dimensional , Hemocytes/metabolism , Hemolymph/metabolism , Immunohistochemistry , Lectins/blood , Lectins/immunology , Mass Spectrometry , Phagocytosis/immunology , Reactive Oxygen Species/metabolism , Respiratory Burst/immunology , Statistics, Nonparametric
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