97 research outputs found

    Potential of selected fungal species to degrade wheat straw, the most abundant plant raw material in Europe

    Get PDF
    Background: Structural component of plant biomass, lignocellulose, is the most abundant renewable resource in nature. Lignin is the most recalcitrant natural aromatic polymer and its degradation presents great challenge. Nowadays, the special attention is given to biological delignification, the process where white-rot fungi take the crucial place owing to strong ligninolytic enzyme system. However, fungal species, even strains, differ in potential to produce high active ligninolytic enzymes and consequently to delignify plant biomass. Therefore, the goals of the study were characterization of Mn-oxidizing peroxidases and laccases of numerous mushrooms as well as determination of their potential to delignify wheat straw, the plant raw material that, according to annual yield, takes the first place in Europe and the second one in the world. Results: During wheat straw fermentation, Lentinus edodes HAI 858 produced the most active Mn-dependent and Mn-independent peroxidases (1443.2 U L-1 and 1045.5 U L-1, respectively), while Pleurotus eryngii HAI 711 was the best laccase producer (7804.3 U L-1). Visualized bends on zymogram confirmed these activities and demonstrated that laccases were the dominant ligninolytic enzymes in the studied species. Ganoderma lucidum BEOFB 435 showed considerable ability to degrade lignin (58.5%) and especially hemicellulose (74.8%), while the cellulose remained almost intact (0.7%). Remarkable selectivity in lignocellulose degradation was also noted in Pleurotus pulmonarius HAI 573 where degraded amounts of lignin, hemicellulose and cellulose were in ratio of 50.4%:15.3%:3.8%. Conclusions: According to the presented results, it can be concluded that white-rot fungi, due to ligninolytic enzymes features and degradation potential, could be important participants in various biotechnological processes including biotransformation of lignocellulose residues/wastes in food, feed, paper and biofuels. Ā© 2017 The Author(s)

    Assessment of efficiency of rare earth elements recovery from lignite coal combustion ash via five-stage extraction

    Get PDF
    Rare earth elements (REE) are frequently referred to as ingredients for enhancements in modern industry, as they are extensively applied in many industrial branches due to their accented electro-magnetic and optical properties. REE have end-utilizations as catalysts, magnets, and as dopants for ceramic materials. Rare earth minerals are scarce therefore the unconventional REE-containing resources such as waste materials and industrial byproducts are continuously being investigated. Coal combustion products comprise REE concentrations varying between 200 ppm and 1500 ppm. This quantity can be isolated though the extraction procedure. In this study, the five stages extraction was conducted on the coal combustion ash from the selected landfill site. The extractions of 32 elements (As, Ga, Ce, Be, Ge, Nd, Cr, Zr, Eu, Cu, Nb, Gd, Co, Mo, Dy, Li, Ag, W, Mn, Cd, Au, Ni, In, Hg, Pb, Sn, Tl, V, Sb, Th, Zn, and La) were conveyed. Chemical analyses were conducted via XRF, ICP-OES, ICP-MS, and AAS techniques. The complexity of the obtained data was examined by Principal component analysis and Cluster analysis in order to derive interconnections between quantity of elements and landfill characteristics, as well as mutual relationships among the elements of interest, and to assess the accomplishment of REE recovery from the coal ash

    LC-MS/MS characterization of phenolic compounds in the quince (Cydonia oblonga Mill.) and sweet cherry (Prunus avium L.) fruit juices

    Get PDF
    Quince and sweet cherry are two common edible fruit-producing trees of temperate regions of Euroasia. The phenolic profiles of juices from quince and sweet cherry fruit extracted by the cold-pressing were analyzed by Ultra-High-Performance Liquid Chromatography (UHPLC). Chromatographical results identified 31 phenolic compounds while quantified thirteen for fruit juices. The quantitative data indicate that the predominant phenolic was 5-O-caffeoylquinic acid in quince (8.343 mg L-1) and cherry juice (6.407 mg L-1). Total Flavonoids (TF), Total Phenolic Content (TPC), and Total Antioxidant Capacity (TAC) were also investigated. In both fruit juices, the TF values varied between 0.30-0.97 g L-1 (Catechin Equivalent) and TPC between 0.36 to 0.94 g L-1 (Gallic Acid Equivalent). It is worth noting that the quince fruit juices possessed a higher TPC and TFC compared to sweet cherry fruit juices

    Microbially-induced deterioration of concrete from hydroelectric power plants ā€“ an initial study

    Get PDF
    Microorganisms can grow on the surface of concrete and inside its pores and microcracks, producing different metabolites. Microbial metabolites, particularly acids, degrade concrete components and enhance its deterioration by abiotic factors. Deterioration of concrete is a serious problem worldwide since it affects construction functionality and requires high maintenance costs.This paper presents microbiological and chemical analyses of 12 concrete samples originating from6 hydroelectric power plants in Serbia, investigated in order to evaluate the key chemical factorsaffecting microbial growth on concrete. In most of the concrete samples, microorganisms from allexamined groups were present in high numbers (bacteria 8.64 Ɨ 103ā€“3.4 Ɨ 108, fungi 9 Ɨ 102ā€“2.08Ɨ 106, sulphur-oxidising bacteria 16.8ā€“2.5Ɨ104 CFU/g). The high number and the presence of variousphysiological groups of microorganisms indicate the high intensity of deterioration caused bybiological sources. Values of pH of the concrete samples were in the range 8.46ā€“11.23, Ca content5.43ā€“19.93%, Fe 151ā€“61100 ppm, sulphate 37.4ā€“623.7 ppm and chloride 96.3ā€“914.1 ppm. Correlation analysis between microbiological and chemical factors indicated a statistically significant strong negative correlation between sulphur-oxidising bacteria and pH (ā€“0.759, p < 0.01)

    Some examples of interactions between certain rare earth elements and soil

    Get PDF
    The rare earth elements represent an increasingly more and more important industrial resource. The increased use may result in waste generation, and their impact upon the environment quality has not been studied sufficiently. Their interaction with soil has been studied in this paper. The Freundlich adsorption isotherm has been determined for lanthanum, erbium and gadolinium at three different soil types (humus, clay and sand type), whereas the sequential extraction at these soil types has been applied for lanthanum and neodymium. The interaction of certain rare earth elements with soil components has been tested as well as the quantity in which these elements are bound to soil and later on extracted in solutions. The objective was to determine the soil capacity for disposal, first of all, of the electronic waste that contains these elements and to assume their fate in the environment.Supplementary material: [https://cherry.chem.bg.ac.rs/handle/123456789/5139

    Deterioration of concrete in hydroelectric power plants- chemical and microbiological factors

    Get PDF
    Degradacija betona može da bude posledica različitih fizičkih promena kao Å”to su korozija, pucanje, preopterećenje itd. Osim fizičkih promena, na izdržljivost betona mogu da utiču i mikroorganizmi u procesu biodeterioracije. Iako biodeterioracija retko može biti direktan uzrok degradacije, ona znatno ubrzava druge Å”tetne procese kao Å”to su prodor hlorida i karbonacija koji naruÅ”avaju strukturu betona [1]. U procesima biodeterioracije mogu da učestvuju različiti mikroorganizmi kao Å”to su bakterije, gljive, alge, liÅ”ajevi [2]. Oni utiču na procese deterioracije betona na tri načina: naruÅ”avanjem izgleda, Å”to je posledica formiranja biofilma, mehaničkim pucanjem usled rasta i kretanja mikroorganizama i hemijskim putem usled ekskrecije metabolita [3]. Na početku, pH betonske povrÅ”ine je veoma visoka, pa će, ukoliko je vlažnost i količina hranljivih supstanci dovoljna, doći do kolonizacije alkalifilnim i tionskim bakterijama. Produkcijom oksidovanih sumpornih jedinjenja snižava se pH vrednost Å”to povećava kolonizaciju betonske povrÅ”ine neutrofilnim, a potom i acidofilnim mikroorganizmima. Osim promene pH vrednosti, kiseline koje se proizvode direktno utiču na strukturni integritet betona poÅ”to razgrađuju cementni materijal [2]. Usled deterioracije, troÅ”kovi održavanja betonskih konstrukcija je povećavaju, Å”to svake godine prouzrokuje znatnu ekonomsku Å”tetu [1, 2, 3]. U okviru ove studije ispitivan je odnos između mikrobnog rasta i različitih hemijskih svojstava uzoraka poreklom iz tri hidroelektrane u Srbiji (HE Đerdap, HE Potpeć, HE Uvac). Uzorkovanje je radjeno na dva mesta na svakoj lokaciji. Ispitivan je broj ukupnih, gvožđevitih, sulfat-redukujućih i tionskih bakterija, kvasaca i plesni kao i pH vrednost i sadržaj sulfata, nitrata, hlorida, mangana, gvožđa, magnezijuma i kalcijuma. Vrednosti pH su bile u opsegu od 8,39- 9,09, koncentracije gvožđa su bile između 151,0- 61.100,0 mg/L, mangana 7,2- 4.900,0 mg/L, sulfata 37,4- 623,7 mg/L, nitrata 1,0- 11,3 mg/L, hlorida 88,2- 1.104,2 mg/L, kalcijuma 5,48- 19,93% i magnezijuma 0,11- 1,26%. Maksimalan broj ukupnih bakterija je bio 6,24x108 cfu/g, kvasaca i plesni 3,12x105 cfu/g, sulfat redukujućih bakterija 2,20x103 cfu/g , tionskih bakterija 2,50x104 cfu/g, a gvožđevitih bakterija 6.4 x 106 cfu/g. Broj mikroorganizama i njihova aktivnost se uobičajeno povezuje sa osnovnim fizičko-hemijskim i hemijskim karakteristikama ispitivanih uzoraka. Hemijski faktori se u ovim uzorcima znatno razlikuju u zavisnosti od mesta uzorkovanja, zbog čega nije moguće odrediti jedan faktor koji bi bio indikator biodeterioracije. Ipak, uzorci uzeti iz HE Đerdap imaju najveći broj tionskih i sulfat-redukujućih bakterija, kao i najveću koncentraciju hlorida. Jedan od uzoraka uzetih iz HE Potpeć imao je najniži broj svih određivanih mikroorganizama kao i ekstremno visoke koncentracije gvožđa i mangana

    Essential Elements as a Distinguishing Factor between Mycorrhizal Potentials of Two Cohabiting Truffle Species in Riparian Forest Habitat in Serbia

    Get PDF
    True truffles (Tuber sp.) that establish ectomycorrhizal symbiosis (ECM) with trees in the Mediterranean and temporal regions have species specific abilities to assimilate soil born elements. Suitable habitats are usually inhabited by few truffle species, while distinguishing their symbiotic potentials appeared very difficult. Two species that commonly inhabit riparian forests in Serbia are the most prized one, Tuber magnatumPico (Piedmont white truffle) and not so highly valued Tuber brumaleVitt. In order to assess potential differences between their assimilation and accumulation abilities, the differences between contents of elements that may be the subjects of the symbiotic trade between the host plant and fungi were evaluated in accumulation target (ascocarps) and their source (the soil). Essential (K, Na, Ca, Mg, Fe, P, S, and Zn) and essential trace elements (Co, Cr, Cu, Mn, and Se) in truffles and soil samples were determined by means of inductively coupled plasma with optical emission spectrometry (ICP-OES). Their concentrations (mg/kg) in ascocarps were in the range from 1.364 +/- 0.591 (Cr) to 10760.862 +/- 16.058 (K), while in soil ranged from 23.035 +/- 0.010 (Cr) to 20809.300 +/- 122.934 (Fe). Element accumulation potential (bioaccumulation factor) was calculated in the system truffle/soil. The statistical approaches were used for establishing the differences, while the possible differentiation between symbiotic potentials of two mycelia in the defined soil conditions was discussed

    Cytotoxicity and antiviral activity of palladium(II) and platinum(II) complexes with 2-(diphenylphosphino)benzaldehyde 1-adamantoylhydrazone

    Get PDF
    Metal coordination compounds have an important role in the development of novel drugs. Using the resazurin microtitration assay we assessed the cytotoxicity and antiviral activity of the ligand 2-(diphenylphosphino) benzaldehyde 1-adamantoylhydrazone and its Pd(II) and Pt(II) complexes. Cytotoxicity was tested in A549 human lung adenocarcinoma epithelial cells. We observed that the ligand displayed a more pronounced cytotoxic activity than the platinum-based drug, carboplatin. Morphological evaluation of A549 cells treated with the ligand by acridine orange and ethidium bromide double staining revealed the presence of signs of apoptosis. Antiviral activity against poliovirus type 1 was assessed by examination of the cytopathic effect (CPE) in Hep-2 cells. Cells that were exposed to the 19 mu M ligand before infection displayed a maximal significant reduction (by 24.42 +/- 1.49%) of the CPE. This was likely due to the inhibition of virus receptors and prevention of viral adsorption. Treatment with 17 mu M Pt(II) complex after viral infection caused a maximal significant reduction (by 30.52 +/- 3.12%) of the CPE, presumably through an effect on viral replication. The results indicate that the ligand should be viewed as a potential anticancer agent. The ligand and the Pt(II) complex show promising results for further investigation of antiviral activity
    • ā€¦
    corecore