Прегледај по Аутор "Svirčev, Zorica"

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    Challenges of using blooms of Microcystis spp. in animal feeds: A comprehensive review of nutritional, toxicological and microbial health evaluation
    (Elsevier, 2021) Chen, Liang; Giesy, John P.; Adamovsky, Ondrej; Svirčev, Zorica; Meriluoto, Jussi; Codd, Geoffrey A.; Mijovic, Biljana; Shi, Ting; Tuo, Xun; Li, Shang-Chun; Pan, Bao-Zhu; Chen, Jun; Xie, Ping
    Microcystis spp., are Gram-negative, oxygenic, photosynthetic prokaryotes which use solar energy to convert carbon dioxide (CO2) and minerals into organic compounds and biomass. Eutrophication, rising CO2 concentrations and global warming are increasing Microcystis blooms globally. Due to its high availability and protein content, Microcystis biomass has been suggested as a protein source for animal feeds. This would reduce dependency on soybean and other agricultural crops and could make use of “waste” biomass when Microcystis scums and blooms are harvested. Besides proteins, Microcystis contain further nutrients including lipids, carbohydrates, vitamins and minerals. However, Microcystis produce cyanobacterial toxins, including microcystins (MCs) and other bioactive metabolites, which present health hazards. In this review, challenges of using Microcystis blooms in feeds are identified. First, nutritional and toxicological (nutri-toxicogical) data, including toxicity of Microcystis to mollusks, crustaceans, fish, amphibians, mammals and birds, is reviewed. Inclusion of Microcystis in diets caused greater mortality, lesser growth, cachexia, histopathological changes and oxidative stress in liver, kidney, gill, intestine and spleen of several fish species. Estimated daily intake (EDI) of MCs in muscle of fish fed Microcystis might exceed the provisional tolerable daily intake (TDI) for humans, 0.04 μg/kg body mass (bm)/day, as established by the World Health Organization (WHO), and is thus not safe. Muscle of fish fed M. aeruginosa is of low nutritional value and exhibits poor palatability/taste. Microcystis also causes hepatotoxicity, reproductive toxicity, cardiotoxicity, neurotoxicity and immunotoxicity to mollusks, crustaceans, amphibians, mammals and birds. Microbial pathogens can also occur in blooms of Microcystis. Thus, cyanotoxins/xenobiotics/pathogens in Microcystis biomass should be removed/degraded/inactivated sufficiently to assure safety for use of the biomass as a primary/main/supplemental ingredient in animal feed. As an ameliorative measure, antidotes/detoxicants can be used to avoid/reduce the toxic effects. Before using Microcystis in feed ingredients/supplements, further screening for health protection and cost control is required.
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    The Late Pleistocene Belotinac section (southern Serbia) at the southern limit of the European loess belt: Environmental and climate reconstruction using grain size and stable C and N isotopes
    (Elsevier, 2013) Obreht, Igor; Buggle, Björn; Catto, Norm; Marković, Slobodan B.; Bösel, Stefanie; Vandenberghe, Dimitri A.G.; Hambach, Ulrich; Svirčev, Zorica; Lehmkuhl, Frank; Basarin, Biljana; Gavrilov, Milivoj B.; Jović, Goran
    The Belotinac loess section is one of the southernmost loess-paleosol environmental archives for the Late Quaternary in Serbia. The climate at this site is intermediate between the continental and the Mediterranean realms, which makes this loess archive potentially highly sensitive to past climatic changes. This paper presents new insights into the paleoenvironmental history during the last glacial period in southern Serbia using grain size and isotope proxy data. The grain size parameters from the Belotinac section reveal variations in the paleowind dynamics and weathering intensity, and suggest the nearby valley of the Južna Morava River as an important source of aeolian sediments in this area. Based on a multiproxy dataset, alternating phases of weak interstadials and phases of enhanced loess deposition at this site were identified. Nitrogen isotope data suggest that during Marine Isotope Stage 3, ecosystems of high biomass productivity and rather open N-cycles prevailed. During Marine Isotope Stage 2, productivity was reduced and the N cycle was more strongly closed, probably due to a shorter growing season and more pronounced temperature decline. Carbon isotope data indicate a possible contribution of C4 plants to the Holocene vegetation, but not to the glacial and interstadial ecosystems of the Late Pleistocene. Changes in atmospheric CO2 level are not reflected in the carbon isotope record. These findings are discussed in the light of paleoclimate proxy datasets from the Morava River valley and Carpathian Basin, as well as through comparison of carbon isotope records from loess sections in SE e Central Europe and in the Rhine Valley. Two different loess provinces exist in terms of glacial-interglacial humidity changes: a province of “glacial drying” and a province of “glacial humidification”. The first includes loess sites under more oceanic influence, where loess d13C records indicate humid interglacials and interstadials and relatively drier glacial periods. The second includes the loess sites of the Carpathian Basin and especially the southern Serbian loess area of Belotinac, where loess d13C records indicate more intensive aridity during interglacials, but a reduced soil moisture deficit and a more humid climate due to lower evapotranspiration in interstadials, and even more in glacial periods.