The purpose of this comparative analysis is the determination of the total quantity of metals (Mg, Ca, K, Ni, Fe, Mn, Zn, Cu, Cr and Pb) in soil samples, above ground plant parts and tea made of plants Teucrium montanum and T. chamaedrys from different serpentine and calcareous habitats as well as of the total quantity of phenolic compounds and antioxidant activity. The obtained results showed that the quantities of certain metals (Mg, Fe, Ni and Mn) in the soil from the serpentine habitats were greater in comparison with other metals (Ca, Zn and Pb) which were more frequently found in the soil from the calcareous habitats. The results demonstrated that the analysed plant samples from the serpentine habitats contained higher quantity of Fe, Ni and Cr as opposed to the plant samples from the calcareous habitats which contained greater quantity of Ca and Zn. Although the studied species accumulate analysed metals in different quantities, depending on the substrate type, they are not hyperaccumulators of these metals. The use of these species from serpentine habitats for tea preparation is safe to a great extent, because in spite of the determined metal absorption by plant organs, the tea does not contain dangerous quantity of heavy metals. The results showed greater total quantity of phenolic compounds and the higher level of antioxidant activity in the plant samples from serpentine habitats in comparison with the samples from calcareous habitats, which is an indicator of one of the mechanisms of adaptation to the serpentine habitat conditions.

To ensure safe food production, cultivar specificity of mineral nutrition in winter wheat was studied in order to determine genotypic differences in the accumulation of several selected microelements (Fe, Mn, Zn and Cu). Soil properties, plant species and genotypes were found to be major factors affecting the uptake of microelements by wheat plants. The application of NPK fertilizers, manure and lime resulted in a decrease in Fe, Mn and Zn contents, but the decrease was not below the concentrations that would make the plants suffer from nutrient deficiencies. In all treatments, the ratio Fe/Mn was <1.5, indicating that iron was not physiologically active, due to which its function was taken over by manganese. The analysis of variance showed highly significant effects of cultivar and fertilization on grain yield and 1,000-grain weight.Keywords: cultivar specificity, fertilization, microelements, wheat Sažetak U cilju proizvodnje zdravstveno-bezbedne hrane, proučavan je uticaj mineralne ishrane kod različitih sorti pšenice kako bi se utvrdile genotipske razlike u akumulaciji određenih mikroelemenata (Fe, Mn, Zn i Cu). Najvažniji faktori koji utiču na usvajanje mikroelemenata od strane pšenice su osobine zemljišta, biljna vrsta i genotipovi. Primena NPK đubriva, stajnjaka i kreča dovela je do smanjenja sadržaja Fe, Mn i Zn, ali Original scientific paper DOI: /10.5513/JCEA01/19.2.2051 Journal of Central European Agriculture, 2018 smanjenje nije bilo ispod koncentracija koje bi izazvele simptome nedostatka kod biljke. U svim varijantama odnos Fe/Mn je bio manji od 1,5 što ukazuje da gvožđe nije fiziološki aktivno, zbog čega je njegovu ulogu preuzeo mangan. Analiza varijanse je pokazala veoma značajne efekte sorte i đubrenja na prinos zrna i težinu 1000 zrna.

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The objective of this study was to determine the allelopathic potential of Robinia pseudoacacia L., Ailanthus altissima (Mill.) Swingle and Amorpha fruticosa L. that grow on the fly-ash deposits at the "Nikola Tesla-A" thermoelectric power plant in Obrenovac. The chemical characteristics of fly ash, such as pH, electrical conductivity (EC), content of carbon (C) and nitrogen (N), contents of available phosphorus (P 2 O 5) and potassium (K 2 O), the contents of total and available Fe, Cu, Mn, Ni and Zn as well as of phenolic acids (3,5 dihydroxybenzoic acid (3,5-DHBA) and ferulic acid) and flavonoids (rutin and quercetin) were analyzed in control fly ash (bare zones without vegetation cover) and plant rhizospheric fly ash. In order to determine the allelopathic activity of phenolic compounds in fly ash, modified soil sandwich allelopathic biotests were performed, and Trifolium pratense L. (red clover) was used as the indicator species. A. fruticosa showed the highest allelopathic activity, followed by A. altissima whereas R. pseudoacacia showed the lowest allelopathic potential. Negative correlation was noted between radicle and hypocotyl growth inhibition of red clover and the pH of fly ash. Positive correlations were found between radicle growth inhibition and the content of C, P 2 O 5 , total concentrations of Cu, available concentrations of Mn and Ni, the contents of ferulic acid, 3,5-DHBA, and rutin. Our results indicate that A. fruticosa and A. altissima increased the content of phenolics in fly ash, which can act as allelochemicals leading to radicle growth inhibition of red clover in the pioneer plant community on fly-ash deposits. These woody species that colonized fly-ash deposits can initiate the beginning of pedogenetic processes altering the ecosystem processes at degraded sites.

The presence of heavy metals (HMs) in the environment represents a serious environmental problem. In this regard, this work was conceived with the aim of finding, among indigenous microorganisms, the species and their combinations with the best biosorption activity for the following HMs: zinc, lead, cadmium, copper, and nickel. The experiment was carried out in several steps: (1) isolation and identification of microbial strains from the Central Effluent Treatment Plant’s wastewater; (2) studying the interaction of microorganisms and the ability to form biofilms in 96-well plates; (3) testing the resistance of biofilms to HMs; (4) testing the growth of biofilms on AMB media carriers in the presence of HMS; and (5) biosorption assay. The selected strains used in this study were: Enterobacter cloacae, Klebsiella oxytoca, Serratia odorifera, and Saccharomyces cerevisiae. The best biofilm producers in control medium were K. oxytoca/S. odorifera (KS), followed by K. oxytoca/S. odorifera/S. cerevisiae (KSC), and E. cloacae/K. oxytoca/S. odorifera (EKS) after 10 days of incubation. Mixed cultures composed of three species showed the highest resistance to the presence of all tested metals. The best biosorption capacity was shown by KSC for Cu2+ (99.18%), followed by EKS for Pb2+ (99.14%) and Cd2+ (99.03%), K. oxytoca for Ni2+ (98.47%), and E. cloacae for Zn2+ (98.06%). This research offers a novel approach to using mixed biofilms for heavy metal removal processes as well as its potential application in the bioremediation of wastewater.