Analiza koncentracije toksičnih i esencijalnih elementa (as, cd, cu, cr, hg, ni, pb, sr, zn) u zooplanktonu sa šaranskog ribnjaka

U poslednjih 20 godina zagađivanje slatkovodnih ekosistema toksičnim elementima je u porastu širom sveta. Zagađenjem su pogođeni pre svega izvori za vodosnabdevanje stanovništva i životno okruženje, ali i industrija kao i privreda uopšte. Međutim zbog perzistentnosti i transfera kroz lance ishrane i potencijalnog akumuliranja u ribama i drugim vodenim organizmima koji se koriste u ishrani, toksični elementi predstavljaju stalnu pretnju ljudskom zdravlju. Zagađivanje naših reka teškim metalima nameće pitanje ne samo zdravstvene ispravnosti riba iz reka već i riba iz ribnjaka obzirom da se većina šaranskih ribnjaka napaja vodom iz sistema kanala DTD. Cilj ove studije je bio da se analizira koncentracija 9 elemenata u zooplanktonu koji predstavlja značajnu prirodnu hranu šarana u poluintenzivnom sistemu gajenja. Istraživanje je obavljeno na 4 ribnjačka objekta, tokom dva ciklusa gajenja šarana, od juna do oktobra, na ribnjaku „Despotovo“. Uzorci zooplanktona za analizu elemenata su uzimani sa tri tačke u svakom jezeru pomoću planktonske mrežice veličine 250 µm jednom mesečno. Na ovaj način su sakupljene samo krupnije veličinske klase zooplanktona (Cladocera i Copepoda), koje šaranska mlađ najviše konzumira. Sa svakog jezera je uziman po još jedan uzorak zooplanktona za kvantitativnu i taksonomsku analizu. Koncentracija elemenata je analizirana induktivno spregnutom plazma masenom (ICP-MS) i optičkom emisionom spektrometrijom (ICP-OES). Rezultati su obrađeni jednofaktorijalnom analizom varijanse (ANOVA) u statističkom programu PAST 3.06. Značajnost razlika testirana je primenom Tukey’s post hoc testa. Podaci su klasifikovani na prolećni, letnji i jesenji aspekt tokom jednog proizvodnog ciklusa. Cladocera su dominirale u populaciji zooplanktona, osim u junu kada su Copepoda bile zastupljenije. Iako nije bilo značajnih razlika u koncentraciji elemenata između godina, osim za Cu i Sr, uočen je karakterističan sezonski obrazac kretanja koncentracija elemenata tokom celog istraživanja. Prolećni i jesenji aspekti u 2012 su bili veći nego u 2013, dok je letnji aspekt u 2013 bio viši nego u 2012. godini. Izuzetak je bila koncentracija Zn u zooplanktonu gde je situacija bila obrnuta. Povišene vrednosti većine toksičnih metala u zooplanktonu na ribnjaku Despotovo se mogu objasniti relativno velikim afinitetom egzoskeleta Cladocera za većinu dvovalentih jona. Nakon adsorbcije elementi na površini ljuštura ovih životinja, tokom vremena bivaju absorbovani kroz telesni zid u unutrašnje organe. Neke studije čak navode da površinski akumulirani kontaminanti na plenu mogu biti dostupniji predatorima od onih akumuliranih u tkivima, zbog niskog pH i visokog nivoa jonske kompleksacije koji vladaju na mestu abstorpcije, u digestivnom traktu većine životinja, Ovi rezultati nameću zaključak da je u budućim istraživanjima kontaminacije vodenih ekosistema i riba poželjno uključiti analize ne samo vode kao izvora toksičnih elemenata, već i odgovarajućih izvora hrane (plena) koji, kako je pokazano, sadrži potencijal ne samo za značajnu akumulaciju elemenata već i njihovu potencijalnu veću biodostupnost konzumentima

Influence of trout farm effluents on selected oxidative stress biomarkers in larvae of Ecdyonurus venosus (Ephemeroptera, Heptageniidae)

The aim of the present study was to establish the extent to which the outlet waters of trout farms affect the ecosystems of the Crnica and Skrapež rivers in Serbia. We monitored selected biomarkers of oxidative stress: superoxide dismutase (SOD), glutathione peroxidase (GPx) and total glutathione (GSH) in larvae of the species Ecdyonurus venosus, and simultaneously analyzed the changes in the physical and chemical parameters. The investigations were carried out in spring at four localities along the Skrapež and Crnica rivers: one upstream (the control localities), and three downstream from the fish farm outlets. On the Skrapež River, the fish farm was clearly visible and was markedly changed by the chemical parameters of the water, manifested as a decreased concentration of dissolved oxygen, increased concentrations of nitrates, nitrites, ammonium ions, total phosphorus and total organic carbon, and increased SOD and GPx activities and decreased GSH concentration in larvae from the first downstream locality as compared to the control locality. On the Crnica River, due to the high values of water flow (around 3 m3/s), effluents from the fish farm had no effect on the chemical parameters of the water or on the tested biomarkers

Oxidation-reduction potential of cerebrospinal fluid as a potential biomarker for ALS progression

Background: ALS is an oxidative stress-related fastpaced motor neuron disease for which there are no accurate biomarkers of progression. This largely hampers the development of therapeutics. Our aim was to test the applicability of oxidation-reduction potential (ORP) of cerebrospinal fluid (CSF) in ALS progression follow-up. Methods: ORP was measured using RedoxSYS (Aytu BioScience, Inc.) in CSF of 49 ALS patients (mean age 63 1.29 years; range 43-80 years; mean ALSFRSr score 37.47 0.90, range 21-48; m/f = 35/14) and 15 controls (mean age 48.93 3.68 years, range 21-67 years; m/f = 10/5). Results: Pearson correlation coefficient (R) between ALSFRSr score and ORP was 0.27 (p = 0.06). R was higher ( 0.45) when two outlier values were excluded from the calculus. Importantly, ALS patients had significantly higher mean ORP (ALS: 121.83 2.76mV; controls: 111.14 2.94 mV; p = 0.033). The difference was also significant for ORP normalized to age. Of note, ORP is reciprocally proportional to the pro-oxidative settings in biological samples. Discussion: Increased ORP values in ALS patients further confirm the role of oxidative stress in this neurodegenerative disease. ORP might find application as a biomarker for ALS progression/prognosis but further measurements on a larger cohort is warranted

Biofizički pristup u rasvetljavanju metabolizma vanadijuma kod gljiva

Vanadijum je esencijalni mikroelement za mnoge žive organizme i učesnik je mnogobrojnih bioloških procesa kod njih. načajnost u ispitivanju ovog elementa porasla je naglo u poslednje tri decenije pretpostavkom o njegovom značajnom doprinosu u tretmanu raznih vrsta bolesti. Skoro sve potrebne informacije koje se tiču oksidacionog oblika, koordinacione geometrije, oligomernog stanja vanadijuma kao i kako prisustvo različitih substrata inhibitora enzimskih aktivnosti utiču na njegove karakteristike se mogu dobiti upotrebom i kombinacijom različitih spektroskopskih metoda. Ispitivanje promena strukture vanadijuma kao potencijalno toksičnog ali i metabolički korisnog elementa je našlo veliku primenu u ispitivanju njegovog metabolizma kod gljiva kao vrste organizama koji imaju sposobnost usvajanja i modulacije različitih vrsta elemenata. Različite vrste gljiva usvajaju vanadijum u različitim oblicima, metabolišu ga na različite načine i imaju različite odgovore na njegovo prisustvo. bog složenih fiziko-hemijskih karakteristika i osetljivosti na uslove u kojima se nalazi, ispitivanje vanadijuma zahteva istovremenu primenu više spektroskopskih tehnika. Primena NMR, EPR, Ramanske, IC, optičke i Rendgenske spektroskopije u izučavanju ovog elementa kod gljiva rasvetljava njegovu ulogu u živim sistemima i daje nam informacije o mogućnostima biotransformacije ovog elementa što može imati značajnu ulogu u mnogim granama nauke a pre svega u medicini i zaštiti životne sredine

Bioaccumulation of heavy metals in Ephemera danica larvae under influence of a trout farm outlet waters

Trout farms are one of the major sources of pollution of highland streams and rivers. Since river sediment burdened with organic pollution binds greater amounts of heavy metals we investigated the influence of the trout farm on the accumulation of metals in the sediment, water and Ephemera danica larvae. Research was conducted seasonally (April, July, and October of 2015 and January of 2016) at one control locality (SK1) and three localities downstream from the farm (SK2-SK4). In agreement with the hypothesis the fish farm discharge induced localized and statistically significant increase of concentrations of Fe, Cu, Cr-,Cr- Ni, Pb and Cd in sediment and E. danica larvae, but not in water at locality SK2 just below the fish farm indicating that sediment is the main source of heavy metals for this organism. However, according to the values of Biota sediment accumulation factor (BSAF) only metals with low sediment concentrations (As, Cd and Cu) accumulated in the larvae. Moreover, BASF values for toxic metals (As, Cd and Cr) showed negative correlation with their concentrations in sediment indicating existence of defense mechanisms in E. danica against assimilation of these metals in high concentrations lethal for it. On the other hand, BSAF values for essential microelements (Cu and Fe) were positively correlated with their sediment concentrations. In conclusion the trout farm induced accumulation of heavy metals in river sediment and E. danica larvae proved to be a good bioindicators of the pollution of river systems by As, Cd and Cu

Influence of a trout farm on antioxidant defense in larvae of Ephemera danica (Insecta: Ephemeroptera)

The aim of this study was to establish the influence of a trout farm on the activity of enzymes superoxide dismutase (SOD) and glutathione peroxidase (GPx), and total glutathione concentration (GSH), in larvae of Ephemera danica, and on environmental parameters in the receiving watercourse. The investigations were carried out seasonally (April, July, and October of 2016 and January of 2017) at four localities (SK1 - control, and SK2, SK3, and SK4 - 30 m, 330 m and 630 m below the fish farm, respectively) along the Skrapez River. Discharged water had the greatest effect on the concentrations of dissolved oxygen (DO), ammonium ions, nitrates (NO3-), and total phosphorus. In the case of SOD and GSH, seasonal changes were greater than longitudinal, with maximal values attained in spring and summer and minimal in autumn and winter. SOD showed the strongest correlation with DO, and GSH with total nitrogen. Activity of GPx demonstrated greater longitudinal variability with maximum at SK2 in all seasons and the strongest correlation with NO3-. The obtained results indicate that GPx activity was the most sensitive to the trout farm effects, while SOD and GSH were more influenced by natural seasonal changes of environmental parameters

INFLUENCE OF VANADIUM ON THE GROWTH AND METABOLISM OF COPRINELLUS TRUNCORUM FUNGAL MYCELIUM

Fungi could absorb heavy metals, metalloids, or radionuclides, thus fungal species possess great potential in bioremediation. Since fungi absorb the vanadium, in the present study ability of Coprinellus truncorum mycelia for vanadate uptake and its intracellular metabolism were investigated. The submerged cultivated C. truncorum was exposed to a rising concentration of vanadate. 31P NMR spectroscopy was used to investigate phosphate metabolism of the mycelium, while the status of vanadium in the cell was followed by 51V NMR spectroscopy. The mycelium could grow, and overcome vanadate presence, up to the concentration of 1.6 mM in the submerged medium. 31P NMR measurements pointed out that vanadate induced changes in the concentration of the crucial metabolite containing phosphorus, particularly sugar phosphates. The major result of vanadate action is evinced through an appearance of a signal positioned at around 2.8 ppm, and an increased signal of hexosephosphates. Using 51V NMR spectroscopy the presence of vanadate monomer in the mycelia of the fungal cell was confirmed

SELENITE METABOLISM IN THE MYCELIUM OF THE FUNGUS PHYCOMYCES BLAKESLEEANUS

In this study, mycelium of fungus Phycomyces blakesleeanus was exposed to soluble toxic form of selenium, selenite (Se+4), with the aim of determining the flow and products of its biotransformation. Selenite is reduced to Se0 in the form selenium nanoparticles (SeNPs) and Se-2 in the form of methylated volatile selenides. Low concentrations of Se+4 in the mycelium form RSSeSR type compounds, which could be a step in the process of SeNPs formation, or incorporation of Se into metabolites such as Se-amino acids

PRODUCTION AND CHARACTERISATION OF SELENIUM NANOPARTICLES BY MYCELIUM OF FUNGUS PHYCOMYCES BLAKESLEEANUS

In this study, mycelium of fungus Phycomyces blakesleeanus was exposed to soluble toxic form of selenium, selenite (Se+4), to examine its ability to reduce it to nanoparticles. Red coloration appeared after only a few hours of incubation with 10 mM Se+4 indicating formation of selenium nanoparticles (SeNPs). SEM-EDS confirmed pure selenium NPs with an average diameter of 57 nm, which indicates to potentially very good medical, optical and photoelectric characteristics. Raman spectroscopy showed several structural forms of SeNPs formed in the extracellular space with a monoclinic Se8 chain as the most represented, and the other observed forms were trigonal Se polymer chain, Se8 ring and Se6 chain structures

Efekti selenita na metabolizam glutationa kod gljive Phycomyces blakesleeanus

Elementarni selen je najmanje biotoksičan oblik selena u prirodi, dok selen-oksianjoni mogu biti toksični zbog značajne pokretljivosti i rastvorljivosti u vodi. Mikrobiološka redukcija selena +4 (selenit) u elementarni selen je stoga od presudnog značaja za smanjenje bioraspoloživosti ovog elementa.1 Visoka reaktivnost selen-oksianjona sa tiolnim grupama, kao i formiranje kiseoničnih radikala u reakciji sa glutationom implicira da oksidativni stres doprinosi toksičnosti selena.2 Tokom biološke redukcije selenita se proizvodi velika količina peroksida čime se indukuje ekspresija gena koji kodiraju enzime antioksidativnog metabolizma, što uključuje i enzime metabolizma glutationa.1 Micelijum gljive Phycomyces blakesleeanus star 24 sata je tretiran 10 mM rastvorom selenita. Uzorci su nakon određenih vremenskih intervala (1, 5, 10, 30, 60 minuta, 24 i 96 sati) ispirani i homogenizovani, nakon čega je meren sadržaj glutationa i specifična aktivnost enzima: peroksidaza (POD), katalaza (CAT), superoksid dismutaza (SOD), glutation peroksidaze (GPx), glutation-S-transferaze (GST) i glutation reduktaze (GR). Nakon dodavanja selenita utvrđen je pad količine ukupnog glutationa u micelijumu. Aktivnost POD i SOD je rasla do 60 minuta, nakon čega je opadala. Aktivnost CAT opadala je odmah po dodatku selenita. Najizraženija je bila promena aktivnosti GPx gde je zabeležen značajan porast, dok su promene aktivnosti GST i GR bile manje izražen