68 research outputs found
Identification of Agrobacterium vitis as a causal agent of grapevine crown gall in Serbia
In 2010, a serious outbreak of crown gall disease was observed on grapevines (Vitis vinifera L. cv. Cabernet Sauvignon) in several commercial vineyards located in the Vojvodina province, Serbia. Bacteria were isolated from the young tumor tissue on nonselective YMA medium and five representative strains were selected for further identification. Tumorigenic (Ti) plasmid was detected in all strains by PCR using primers designed to amplify the virC pathogenicity gene, producing a 414-bp PCR product. The strains were identified as Agrobacterium vitis using differential physiological and biochemical tests, and a multiplex PCR assay targeting 23S rRNA gene sequences. In the pathogenicity assay, all strains induced characteristic symptoms on inoculated tomato and grapevine plants. They were less virulent on tomato plants in comparison to the reference strains of A. tumefaciens and A. vitis. [Ministarstva nauke Republike Srbije, br. III46008: Development of integrated management of harmful organisms in plant production in order to overcome resistance and to improve food quality and safety
Prisustvo Listerija vrsta u uzorcima riba, proizvoda od ribe i morskih plodova
Listeria monocytogenes is a bacterium that is pathogenic for man and for most animal species. Listeriosis is a generalized infection that starts after ingestion of the causative agent L. monocytogenes (Finlay, 2001). Food that is not properly thermically processed, long storage of such food, food that is produced in inadequate hygienic food plants, as well as cooked-cooled ready to eat food (RTE) is the ideal medium for listeria multiplication. High risk food originated from fish, fish products and sea products comprised of: molluscs (fresh of frozen shellfish, crustaceans shelled or not), fresh fish (ready to eat without cooking), fish products packed with brine (NaCl lt 6%), (salted, marinated, fermented, cold smoked and fish in brine), thermically treated fish and crustacean products (pasteurization, cooking, hot smoking, including pre-cooking and panning). In this research, fish samples, fish products and sea products from Serbian markets were examinated such as: fresh fish (cooled), frozen food (fish and sea products - cuttlefish, squid, octopus, shellfish, crustaceans and shrimps), panned products; smoked fish, salted fish, thermally treated fish and fish products, semi-canned fish and canned fish. Microbiological testing has been performed according to internationally prescribed standards ISO 11290-1 (1996) 'Microbiology of food and animal feed stuffs - Horizontal method for the detection and enumeration of Listeria monocytogenes'. There were 470 samples from fish products and sea products. Presence of Listeria spp was registered in 58 samples (12.34%). Listeria monocytogenes was found in 1.92% samples (9 isolates), which makes 15.52% of the total Listeria that were isolated from the tested food. Other isolated Listeria belong to the following species: L. innocua (8.51%), L.welshimeri (1.28%), L.welshimeri/innocua (0.21%), L. grayi (0.21%) and L. seeligeri (0.21%). Exceptional viability of Listeria monocytogenes in the food tested was documented, also (freezing temperature - 18oC, five months).Listeria monocytogenes je bakterija patogena za ljude i veliki broj životinjskih vrsta. Listerioza predstavlja generalizovanu infekciju koja nastaje nakon oralne ingestije uzročnog agensa L. monocytogenes (Finlay, 2001). Navedena bakterija se najbolje razvija u namirnicama koje nisu adekvatno termički obrađene; koje su dugo skladištene; koje su proizvedene na mestu na kojem principi higijenskog rukovanja hranom nisu sprovođeni; kuvano-hladnoj hrani spremnoj za jelo (ready to eat food - RTE) U visoko rizične namirnice počev od vrsta ribe, proizvoda od ribe i plodova mora ubrajaju se: mekušci (sveže i zamrznute školjke, rakovi u ljušturama, ili očišćeni), sveža riba (koja se konzumira bez termičke obrade), riblji proizvodi u vodenom rastvoru soli (NaCl%), (soljena, marinirana, fermentisana, hladno dimljena i riba u sopstvenom soku), srednje termički obrađeni riblji proizvodi i rakovi (pasterizacija, kuvanje, toplo dimljenje, uključujući i pred-kuvanje i panirani proizvodi). Kao materijal za ispitivanje korišćeni su uzorci riba, proizvoda od riba i morski plodovi: sveža riba (u rashlađenom stanju), zamrznute namirnice (riba i morski plodovi - lignje, sipe, hobotnice, školjke, rakovi i škampi), panirani proizvodi, dimljena riba, usoljena riba, termički obrađena riba i proizvodi od ribe, polukonzerve i konzerve od ribe. Mikrobiološko ispitivanje je rađeno prema propisanoj metodi po Međunarodnom standardu ISO 11290-1 (1996) 'Microbiology of food and animal feeding stuffs - Horizontal method for the detection and enumeration of Listeria monocytogenes'. Ukupno je ispitano 470 uzoraka ribe, proizvoda od ribe i morskih plodova. Prisustvo Listeria vrsta utvrđeno je u 58 uzoraka (12,34%). Listeria monocytogenes je utvrđena kod 1,92% pregledanih uzoraka (9 izolata) i čini 15,52% od svih vrsta iz roda Listeria koje su izolovane iz navedenih namirnica. Ostale vrste listerija koje su izolovane pripadale su: L. innocua (8,51%), L. welshimeri (1,28%), L. welshimeri/innocua (0,21%), L. grayi (0,21%) i L. seeligeri (0,21%). Ustanovljena je izuzetna sposobnost preživljavanja pri niskim temperaturama vrste Listeria monocytogenes u namirnicama koje su čuvane pri temperaturi od -18oC tokom 5 meseci
Stipetum novakii ass. nova – a new association of serpentine rocky grassland vegetation (Halacsyetalia sendtneri) in Serbia
Phytosociological characteristics of grassland communities above serpentines (order Halacsyetalia sendtneri H. Ritter-Studni~ka 1970) in Serbia, are analyzed according to Braun-Blanquet methodology. In order to detect the basic floristic differentiation of analyzed communities ordinary correspondence analysiswas applied. Cluster analysis was also performed to see the structure and separation of the communities based on the floristic composition. In order to determine diagnostic species, fidelity indices with presence/ absence data and the size of all groups standardized to equal size were calculated. The new association Stipetum novakii is described in open rocky serpentine grasslands in Brdjani Gorge
The chitinolytic activity of the Curtobacterium sp. isolated from field-grown soybean and analysis of its genome sequence.
Curtobacterium sp. GD1 was isolated from leaves of conventionally grown soybean in Brazil. It was noteworthy that among all bacteria previously isolated from the same origin, only Curtobacterium sp. GD1 showed a strong chitinase activity. The enzyme was secreted and its production was induced by the presence of colloidal chitin in the medium. The chitinase was partially purified and characterized: molecular weight was approximately 37 kDa and specific activity 90.8 U/mg. Furthermore, Curtobacterium sp. GD1 genome was sequenced and analyzed. Our isolate formed a phylogenetic cluster with four other Curtobacterium spp. strains, with ANIb/ANIm � 98%, representing a new, still non described Curtobacterium species. The circular genome visualization and comparison of genome sequences of strains forming new cluster indicated that most regions within their genomes were highly conserved. The gene associated with chitinase production was identified and the distribution pattern of glycosyl hydrolases genes was assessed. Also, genes associated with catabolism of structural carbohydrates such as oligosaccharides, mixed polysaccharides, plant and animal polysaccharides, as well as genes or gene clusters associated with resistance to antibiotics, toxic compounds and auxin biosynthesis subsystem products were identified. The abundance of putative glycosyl hydrolases in the genome of Curtobacterium sp. GD1 suggests that it has the tools for the hydrolysis of different polysaccharides. Therefore, Curtobacterium sp. GD1 isolated from soybean might be a bioremediator, biocontrol agent, an elicitor of the plant defense responses or simply degrader
The use of nanoparticles to improve the analytical capabilities of LIBS for solution sample analysis
Laser-induced breakdown spectroscopy (LIBS) is a diagnostic technique based on optical emission spectroscopy, suitable for rapid, in situ, and multi-element analysis of all sample types. LIBS has demonstrated its greatest potential in the analysis of solids, both conducting and nonconducting. However, when it comes to quantitative LIBS analysis of liquids, there are still some drawbacks that limit its applicability, such as poor repeatability and low sensitivity. To some extent LIBS performance may be improved if directly performing LIBS on the solution is avoided by converting the liquid into a solid phase. Another recently proposed method to resolve the difficulties in LIBS analysis of liquid samples is the application of Nanoparticle - Enhanced LIBS (NELIBS) [1,2]. The aim of the present work was to examine the effect of copper oxide nanoparticles (NPs) on the analytical capabilities of LIBS analysis of lead in aqueous solutions. The apparatus for NELIBS experiments comprises a laser source, a spectrograph (F=850 mm, grating 1800 groves/mm, F/11) coupled with a CCD, and the focusing and collecting optics, i.e. the same as used in conventional LIBS. A double pulse Q-switched Nd:YAG laser at 1064 nm, pulse duration 10 ns, pulse energy 50 mJ, interpulse delay 1 μs was used. The spectra were registered in a time-integrated mode (integration time 1 ms). A glass plate was chosen as the substrate to ensure there is no interference between NPs and the substrate. The first type of samples was prepared by drying a droplet of a Pb solution (10 μl, concentration 100 ppm) on the glass substrate. The second type was prepared by drying a droplet of the copper oxide colloidal solution on the glass, prior to the deposition of the analyte solution. Three sets of the LIBS spectra were acquired; spectra of glass with deposited CuO NPs, of glass with deposited sample solution of Pb, and of the glass with deposited NPs of CuO and the sample solution of Pb. The spectra were obtained in the 395-415 nm spectral range. Only in the third case, intense Pb lines appeared in the spectrum. Estimation of the limit of detection (LOD) for the resonance Pb line at 405.78 nm, without additional optimization of the measurement parameters, gave a value of 3.6 ppm. Regarding the fact that without the addition of the NPs layer no analyte signal was obtained, it can be concluded that the enhancement of the lead emission line intensity is caused by the presence of the NPs, i.e. by the lower plasma formation threshold and more efficient atomization of the analyte deposited on the NP layer. The main benefits of using NELIBS for the analysis of solutions lie in its simplicity, speed, the small amount of solution needed (few microliters), and the ability to analyze very dense or slurry samples.VII International School and Conference on Photonics : PHOTONICA2019 : Abstracts of Tutorial, Keynote, Invited Lectures, Progress Reports and Contributed Papers; August 26-30; Belgrad
The ethics of community-based research with people who use drugs: results of a scoping review
Social changes and changes of values
The aim of our investigation was to find out to what extent the dramatic social changes which happened in the period between 1988 and 1994 (disintegration of the state, the war, international sanctions, isolation, rapid impoverishment, etc.) reflected upon value system of youth in Serbia. The values were investigated through the following groups of variables: ranking social goals by priority, acceptance of value orientations, life-style preferences, expectations from future career, and choice of model figures. At the end of 1988, a sample of 14- year-old pupils (N=595) were questioned throughout Serbia. At the beginning of 1994 a sample of 14-year-old pupils (N=341) from the same regions of Serbia were questioned in the same way. The overall results show that the most marked changes happened within those values which were ideologically relevant. Also, a decrease of prosocial orientation and an increase of utilitarian-hedonistic values were noticed. Although there were numerous statistically significant differences (30 out of 42 comparisons were significant at 0.05) the intensity of changes and their hierarchy indicate that social changes were much more profound than the trace they left on the values of youth of this age
Retypification of the name Eryngium palmatum (Apiaceae)
Kuzmanović, Nevena, Clementi, Moreno, Kabaš, Eva, Vukojičić, Snežana (2013): Retypification of the name Eryngium palmatum (Apiaceae). Phytotaxa 105 (2): 58-60, DOI: 10.11646/phytotaxa.105.2.5, URL: http://dx.doi.org/10.11646/phytotaxa.105.2.
Typification of five names listed by Roberto de Visiani in Plantarum Serbicarum Pemptas
Clementi, Moreno, Kuzmanović, Nevena, Barina, Zoltan, Lakušić, Dmitar, Vukojičić, Snežana (2014): Typification of five names listed by Roberto de Visiani in Plantarum Serbicarum Pemptas. Phytotaxa 170 (1): 57-60, DOI: 10.11646/phytotaxa.170.1.9, URL: http://dx.doi.org/10.11646/phytotaxa.170.1.
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