Speciation of phytate ion in aqueous solution. Sequestering ability toward mercury(II) cation in NaClaq at different ionic strengths     

De Stefano C  Milea D  Porcino N  Sammartano S 《Journal of agricultural and food chemistry》2006,54(4):1459-1466

As a contribution to understanding the speciation of mercury in the environment and to the study of the sequestering ability of phytate (Phy) toward heavy metal and organometal cations, this paper describes the results of an investigation (at t = 25 degrees C by potentiometry, ISE-H+ glass electrode) of its interactions with mercury(II) cation in NaCl aqueous solutions at different ionic strengths (I = 0.15 and 1.0 mol L(-1)), in the pH range 2.5 < or = pH < or = 9.5 and considering metal-to-ligand ratios of 1:1 < or = Hg/Phy < or = 4:1. The formation of 11 HgiHjPhy(12-2i-j)(- species with i = 1 and 0 < or = j < or = 7 and i = 2 and 0 < or = j < or = 2 was observed. Their complex formation constant values proved to be fairly dependent on ionic strength. The speciation of phytic acid and mercury(II) is also dependent on the metal-to-ligand ratio; the dependence of the stability of phytate-mercury(II) species on the phytate protonation step was modeled, and an empirical predictive relationship was proposed. From the results obtained, phytate has very good sequestering ability toward Hg2+, even in the presence of considerable excesses of chloride ion, that is, another ligand strongly interacting with mercury; this supports future studies both on the use of plants that naturally synthesize it for phytoremediation purposes and on its direct application in remediation techniques.  相似文献   

Vibrio spp. Control at Brine Shrimp,Artemia, Hatching and Enrichment     

Juliana Aguiar Interaminense  Nathalia Ferreira Calazans  Bruna Critas do Valle  Joana Lyra Vogeley  Sílvio Peixoto  Roberta Soares  Jos Vitor Lima Filho 《Journal of the World Aquaculture Society》2014,45(1):65-74

Experiments were conducted to evaluate different prophylactic methods to control the bacterial load in brine shrimp, Artemia, hatching. The first experiment evaluated three treatments to control Vibrio spp. during the Artemia hatching: microalgae (Chaetoceros calcitrans), probiotic (Bacillus spp.), and antibiotic (Florfenicol). In the second experiment, Artemia metanauplius were enriched in distinct treatments with C. calcitrans, probiotic, and emulsion rich in docosahexaenoic and eicosapentaenoic fatty acids. Enriched Artemia metanauplius and nauplii (control) were offered to white shrimp, Litopenaeus vannamei, postlarvae (PL₇–PL₁₉). Presumptive Vibrio were quantified in Artemia, PL, and rearing water. Microalgae and probiotic were effective to control Vibrio spp. in Artemia nauplii. The enrichment process increased the Artemia bacterial load but did not affect Vibrio load in L. vannamei.  相似文献   

Development of a Chemosensor for the In Situ Monitoring of Thallium in the Water Network     

Monica Puccini  Lorenzo Guazzelli  Andrea Luca Tasca  Andrea Mezzetta  Christian Silvio Pomelli 《Water, air, and soil pollution》2018,229(7):239

Thallium is an emerging contaminant, which can be retained in scale encrustation within the pipeline and then released to drinking water. It is included in the Priority Pollutant List of the U.S. EPA. In this study, a sample from the water pipeline of Pietrasanta (Italy), affected by the contamination of thallium, is characterized by SEM-EDS, TGA, and FT-IR. Fluorescence spectroscopy is then proposed as the optimal technique for the detection of the contaminant. The functionality of a previously reported fluorescent calix[4]arene-based chemosensor is verified first on a standard solution of thallium nitrate and then on the sample under investigation. The quenching of the fluorescence of the sensor during the complexation of thallium is confirmed, identifying an ON-OFF sensor with high sensitivity, able to detect concentrations as low as 10^?6 M and with high potential of development for the in situ and fast monitoring of the pollutant in the water network.  相似文献   

Removal of Phenolic Compounds from Aqueous Solutions Using Sludge-Based Activated Carbons Prepared by Conventional Heating and Microwave-Assisted Pyrolysis     

Glaydson S. dos Reis  Matthew A. Adebayo  Carlos H. Sampaio  Eder C. Lima  Pascal S. Thue  Irineu A. S. de Brum  Silvio L. P. Dias  Flavio A. Pavan 《Water, air, and soil pollution》2017,228(1):33

Sludge-derived activated carbons (ACs) were prepared by conventional heating and microwave pyrolysis. The ACs were characterized using several analytical and functional techniques and used for removal of six phenolic compounds from aqueous solutions. The adsorbents exhibited similar features and possessed hydrophobic surfaces. The ACs were assigned mesoporous materials, with specific surface areas of up to 641 and 540 m² g^?1 for CAC-500 and MAC-980, respectively. The preliminary results indicated that phenol removal onto the ACs increased in the order: m-cresol?<?phenol?<?o-cresol?<?2-chrorophenol?<?2-nitrophenol?<?hydroquinone. Hydroquinone exhibited the highest adsorption capacity and was chosen to continue the remaining part of the experimental work—kinetic and isothermal studies. The adsorption kinetic and isotherm data were well described by the Avrami fractionary order and Redlich–Peterson models, respectively. The maximum amounts (Q _max) of hydroquinone adsorbed at 25 °C were too high, reaching 1218.3 and 1202.1 mg g^?1 for CAC-500 and MAC-980, respectively. The mechanism of adsorption was proposed in this work, and it was suggested that donor–acceptor complex and π–π interactions play major roles in the adsorption process. The adsorbents were also tested on simulated effluents. The two ACs displayed good efficiency for the treatment of industrial simulated effluents.  相似文献   

Genetic assessment of apple germplasm in Bosnia and Herzegovina using microsatellite and morphologic markers     

Fuad Gasi  Silvio Simon  Naris Pojskic  Mirsad Kurtovic  Ivan Pejic 《Scientia Horticulturae》2010

Traditional apple cultivars from Bosnia and Herzegovina (B&H), potentially diverse due to specific geographic location and history of the country, represent a possible source of valuable traits for future breeding efforts and sustainable fruit growing. A total of 39 accessions, 24 traditional B&H cultivars and 15 modern international cultivars, maintained at the ex situ apple collection “Srebrenik” in Northeast Bosnia were, investigated using 10 SSR (simple sequence repeats) markers and 23 morphologic characteristics. All the used primer pairs manage to amplify clearly distinguishable and highly polymorphic SSR alleles, in average 10.4 alleles per locus. More than two different alleles per locus were detected for seven accessions (five traditional B&H cultivars and two international cultivars). Forty one unique alleles were exclusively present within the B&H cultivars, while seven unique alleles were only detected within international cultivars. The differentiation between traditional B&H and international cultivars (Fst = 0.060; P < 0.0001) was significant, also confirmed by analyses of molecular variance (AMOVA) (f_CT = 0.092; P < 0.001). Cluster analyses of 39 apple accessions, based on 10 SSR loci, revealed that only two traditional B&H cultivars grouped tightly with international cultivars (Ljepocvjetka and Bobovec Jon), while the rest formed separate clusters. Multivariate analyses of variance (MANOVA), nonparametric multivariate analyses of variance (NPMANOVA) and analyses of similarity (ANOSIM) showed statistically significant difference in morphologic characteristics between traditional B&H cultivars and the international cultivars. Cluster analyses of 39 apple accessions, based on the morphologic data, displayed less differentiation between traditional and international accessions, in comparison to the cluster analyses based on molecular data. No correlation between the molecular and morphologic data set was detected using the Mantel test. Many of the morphologic characteristics which have been analyzed in this study have significant commercial importance, we can assume that unlike the microsatellites these traits have been under agronomic selection pressure.  相似文献   

Cadaveric sperm viability in the white shrimp Litopenaeus vannamei          下载免费PDF全文

Thaís Castelo‐Branco  Bruna Paula Torres Quinto  Roberta Soares  Maria Madalena Pessoa Guerra  Silvio Peixoto 《Aquaculture Research》2016,47(10):3350-3351

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Species-specific DNA markers for identification of two root-knot nematodes of coffee: Meloidogyne arabicida and M. izalcoensis     

Valdir Ribeiro Correa  Marcilene Fernandes Almeida dos Santos  Maria Ritta Alves Almeida  José Ricardo Peixoto  Philippe Castagnone-Sereno  Regina Maria Dechechi Gomes Carneiro 《European journal of plant pathology / European Foundation for Plant Pathology》2013,137(2):305-313

Seven root-knot nematodes (RKN), including Meloidogyne exigua, M. incognita, M. paranaensis, M. enterolobii, M. arabicida, M. izalcoensis and M. arenaria are major pathogens of coffee crop in the Americas. Species-specific primers for their identification have been developed for five of them and constitute a fast and reliable method of identification. Here we report a PCR-based assay for specific detection of M. arabicida and M. izalcoensis. Random Amplified Polymorphic DNA fragments specific for these two species were converted into sequence characterized amplified region (SCAR) markers. PCR amplification using the SCAR primers produced a specific fragment of 300 bp and 670 bp for M. arabicida and M. izalcoensis, respectively, which were absent in other coffee-associated Meloidogyne spp. tested. SCAR primers also allowed successful amplification of DNA from single second-stage juveniles (J2), males and females. In addition, these primers were able to unambiguously detect the target species in nematode suspensions extracted from soil and roots samples, in different isolates of the same species or when used in multiplex PCR reactions containing mixtures of species. These results demonstrated the effectiveness of these SCAR markers and their multiplex use with those previously developed for M. exigua, M. incognita, M. paranaensis, M. enterolobii and M. arenaria constitute an essential detection tool. This diagnostic kit will contribute for specific J2 identification of the major RKN infecting coffee from field samples in the Americas.  相似文献   

Multielemental Determinations in Chocolate Drink Powder Using Multivariate Optimization and ICP OES     

RR Peixoto  A Oliveira  S Cadore 《Journal of agricultural and food chemistry》2012,60(33):8117-8122

In this work multivariate experiments were conducted to optimize the operating conditions for inductively coupled plasma optical emission spectrometry (ICP OES) for multielemental determinations in chocolate drink powder. The operating conditions were investigated using a 2(3) central composite design, where the variables studied were radio frequency power, nebulization flow rate, and auxiliary argon flow rate. The effects of these parameters on plasma robustness and on signal to background ratio (SBR) were considered in parallel, allowing the evaluation of robustness and detectability using few and fast experiments to select the best conditions for the determination of the analytes. In this case, the proposed experiments were applied to the optimization of a method aimed at the determination of Al, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, P, Pb, V, and Zn in chocolate drink powder. The compromise conditions that allowed obtaining a robust and sensitive analytical method were radio frequency power of 1200 W, nebulization flow rate of 0.6 L/min, and auxiliary argon flow rate of 0.3 L/min. Using these conditions, recoveries between 95 and 105% and relative standard deviations lower than 5% were obtained for the majority of the analytes. The proposed method was successfully applied to the analysis of 15 samples of chocolate drink powder. The highest concentrations of metallic species were found in diet and light products.  相似文献   

Prevalence of antibodies against Toxoplasma gondii among Brazilian white-eared opossums (Didelphis albiventris)     

Fornazari F  Teixeira CR  da Silva RC  Leiva M  de Almeida SC  Langoni H 《Veterinary parasitology》2011,179(1-3):238-241

Considering that Toxoplasma gondii is a parasite of global importance which affects several animal species including humans, the current study aimed to investigate the prevalence of antibodies against T. gondii among 72 white-eared opossums (Didelphis albiventris) from Botucatu Municipality (22°53'S 48°26'W), S?o Paulo State, Brazil. The investigation was carried out from January 2008 to December 2009, when the animals had their blood samples collected and subjected to the modified agglutination test (MAT); 12 specimens had brain samples bioassayed in mice. Seroprevalence was 5.5% (n=4) and bioassays were negative. Older animals had higher prevalence of antibodies against T. gondii. Opossums in closer contact with the urban environment are likely more exposed to T. gondii than animals from the sylvatic environment.  相似文献   

The presence of methicillin-resistant Staphylococcus aureus on large pig breeding farms in Croatia     

Habrun B  Račić I  Beck R  Budimir A  Benić M  Kompes G  Spičić S  Cvetnić Z 《Acta veterinaria Hungarica》2011,59(4):419-425

Methicillin-resistant Staphylococcus aureus (MRSA) have emerged worldwide and have become resistant to a variety of antibiotics. MRSA colonisation in pigs was first reported from the Netherlands in 2005, where pigs were implicated as a source of human MRSA infections (Voss et al., 2005). This paper presents the first report on the presence of MRSA on large pig breeding farms in Croatia, together with the determination of the mecA gene, the results of spa typing and susceptibility to commonly used antimicrobials. Dust samples (7-11 per farm) were collected from eight large pig farms in Croatia. Of the total 68 swabs, the mecA gene was detected in 24 isolates growing on the MRSA agar. All isolates were resistant to oxacillin, tetracycline and streptomycin, and susceptible only to vancomycin, while 92% of the strains were susceptible to ciprofloxacin. Genotyping of the MRSA strains was performed by spa typing, and revealed t011 (n = 17), t034 (n = 5) and t1451 (n = 2). The results presented here predict that MRSA is present on a large number of pig farms in Croatia.  相似文献