Trace metals accumulation in the eco-system water - soil - vegetation (Agropyron cristatum) - common voles (Microtus arvalis) - parasites (Hymenolepis diminuta) in Radnevo region, Bulgaria.

BACKGROUND: Coal and coal processing industries provoke trace metal pollution, which has a negative effect on the water - soil - vegetation - small mammals eco-system, constituting part of the food chain and exerting a serious impact on human health. OBJECTIVES: Assessment of the environmental impact of Maritza iztok coal complex, situated east of Radnevo town, Bulgaria, by tracking the dynamics and accumulation of trace metals in the eco-system water - soil - vegetation - common voles - parasites. METHODS: Samples from surface waters, their nearby uncultivated soils, meadow uncultivated vegetation (Agropyron cristatum) and field common voles (Microtus arvalis) were collected. In situ measurements and laboratory extraction procedures and analyses were performed. Accumulation and mobility indices were calculated. The distribution of dissolved Mn, Ni, Cu, Zn and Pb chemical species in water-soil extracts was calculated using a thermodynamic approach. Two thermodynamic models were applied - the classical ion-association model for calculating the inorganic trace metal species and the Stockholm Humic Model (SHM) accounting for the complexation reactions of trace metals with organic matter. Visual Minteq computer program, Version 3.1 was used. The relationship chemical species - bioaccumulation was discussed. RESULTS: Pb and Mn, together with SO42- and PO43- were found to be the main pollutants of waters in the region. The soils studied exhibited low concentrations of trace metals, not exceeding the specified MACs. The content of Mn was the highest, followed by Zn, Pb, Cu and Ni. The highest phytoaccumulation coefficients in the studied uncultivated grass vegetation were calculated for Cu and Zn, being 1-2 orders of magnitude higher than those of Mn and Ni. The accumulation of trace metals was explained on the basis of ions mobility and chemical species distribution. In the case of the host-parasite system Microtus alvaris - Hymenolepis diminuta, Zn displays the highest accumulation coefficient, followed by those of Cu and Pb. The parasite showed a higher bioaccumulation compared to infected common voles, with the highest bioaccumulation found for Ni. CONCLUSIONS: The bioaccumulation of trace metals depends on their mobility, concentration and chemical forms in water-soil solutions. Metal-organic species stimulate the phytoaccumulation of trace metals while inorganic ones suppress it. The sequence of trace metals bioaccumulation in common voles is analogous to that of soil contamination. The parasite exhibited higher bioaccumulation levels compared to infected common voles.

Traditionally used medicinal plants against uncomplicated urinary tract infections: Hexadecyl coumaric acid ester from the rhizomes of Agropyron repens (L.) P. Beauv. with antiadhesive activity against uropathogenic E. coli.

The rhizomes from Agropyron repens are traditionally used for the treatment of uncomplicated urinary tract infections. Extracts prepared with solvents of different polarity did not show any cytotoxic effects against different strains of uropathogenic E. coli (UPEC) and human T24 bladder cells under in vitro conditions. Significant antiadhesive activity against the bacterial attachment to human T24 bladder cells was found for an acetone extract (AAE) at concentrations >250µg/mL. More hydrophilic extracts did not influence the bacterial attachment to the eukaryotic host cells. Bioassay guided fractionation of AAE led to the identification of (E)-hexadecyl-3-(4-hydroxyphenyl)-acrylate (hexadecyl-coumaric acid ester) 1 as the compound responsible for inhibiting the UPEC adhesion to T24 bladder cells. 1 reduced the bacterial invasion into the bladder cells as shown by a specific invasion assay. Additionally, 1 was obtained by chemical synthesis, and also the synthetic structural analogs 2 and 3 were tested for their potential antiadhesive activity, indicating that a shorter alkyl chain at the ester function as well as the lack of hydroxylation of the phenyl moiety will abolish the antiadhesive activity.

Effect of biological pretreatment of Agropyron elongatum 'BAMAR' on biogas production by anaerobic digestion.

The aim of this work was to analyze the impact of three different moisture contents (MC), at 45% MC, 65% MC, 75% MC, on the degradation of cellulose, hemicellulose, and lignin during fungi treatment by Flammulina velutipes of Agropyron elongatum 'BAMAR' and on biogas production. The analysis of chemical composition shown that F. velutipes had greater selectivity for lignin biodegradation with the highest hemicellulose and lignin removal at 29.1% and 35.4%, respectively, and lowest cellulose removal (20.48%) at 65% MC. F. velutipes cultivated at 65% MC increased biogas production of 398.07Ndm(3)kg(-1)VS(-1), which was 120% higher than the untreated sample. These treatment conditions resulted in 134% more methane yield compared with untreated sample. The results of this study suggested that A. elongatum is a potential biomass for biogas production in agriculture biogas plant and white-rot fungus F. velutipes provides an effective methods for improve biodegradation of A. elongatum.

Metals and arsenic in soils and corresponding vegetation at Central Elbe river floodplains (Germany).

Floodplain soils at the Elbe river are frequently polluted with metals and arsenic. High contents of these pollutants were detected down to subsoil layers. NH4NO3-extractable (phytoavailable) Cd, Ni, and Zn were elevated in horizons with high acidity. Among five common floodplain plant species, Artemisia vulgaris showed highest concentrations of Cd, Cu, and Hg, Alopecurus pratensis of As and Phalaris arundinacea of Ni, Pb, and Zn. Relationships were weak between metal concentrations in plants and phytoavailable stocks in soil. As and Hg uptake seems to be enhanced on long submerged soils. Enrichments of Cd and Hg are linked to a special plant community composition. Grassland herbage sampled in July/August revealed higher concentrations of As (+122%), Hg (+124%), and Pb (+3723%) than in May. To limit harmful transfers into the food chain, low-lying terraces and flood channels revealing highest contaminations or phytoavailabilities should be excluded from mowing and grazing.

Two quality-associated HMW glutenin subunits in a somatic hybrid line between Triticum aestivum and Agropyron elongatum.

High-molecular-weight glutenin subunits (HMW-GSs) from hybrid line II-12 between wheat (Triticum aestivum L.) and Agropyron elongatum (Host) Nivski were characterized with SDS-PAGE. Out of these HMW-GSs, two subunits, h1Bx and h1By, had mobilities similar to the subunits 1Bx13 and 1By16 from common wheat 4072, which was used as control. Polyclonal antibodies (pAbs) of h1Bx and h1By were prepared, and Western blotting showed that the pAbs had strong affinities for h1Bx and h1By, separately. The specificity of h1Bx-pAb was further checked; it preferentially recognized subunits h1Bx and 1Bx13. HMW-GS gene coding sequences were amplified by genomic polymerase chain reaction from hybrid II-12. Two of the five amplicons, marked II2a and II31b, were sequenced. Their coding sequences are clustered to Glu-1Bx7 and Glu-1By9 of common wheat. Three discrepant regions in deduced amino acid sequences of II2a and 31b repeated one time more than Glu-1Bx7 and Glu-1By9. N-terminal sequences of h1Bx and h1By were determined, which were identical to the published sequences of 1Bx13 and 1By16 and in agreement with that deduced from II2a and II31b, respectively. These results indicated that the two novel genes separated from the hybrid wheat derived from the allelic variation of 1Bx7 and 1By9 of the parent wheat. There is an additional cysteine residue positioned at 271st amino acid of the mature peptide of II2a, which may be related to the high quality of the flour.

Fructans in crested wheatgrass leaves.

Crested wheatgrass is an important cool-season grass that has become naturalized in many semiarid regions of the western U.S. It provides ground cover and reduces soil erosion caused by water and wind. Additionally, crested wheatgrass produces important forage for livestock and wildlife on 6 to 8 million hectars of western rangeland. It is well adapted to semiarid cold desert regions because of its cool temperature growth and drought tolerance. Understanding the biosynthesis of fructans in crested wheatgrass is important because of their likely role in both cool temperature growth and drought tolerance. Recent research described a major gene (6-SFT) in crested wheatgrass that is involved in fructan biosynthesis. 1-kestotriose, the major DP3 fructan in crested wheatgrass, serves as the substrate for the two major DP4 fructans, 1&6-kestotetraose and 1,1-kestotetraose. The three major DP5 fructans are 1&6,1-kestopentaose, 1,1&6-kestopentaose and 1,1,1-kestopentaose. The major DP6 fructan is 1&6, 1&6-kestohexaose. We postulate that 1&6,1&6-kestohexaose is synthesized from the addition of a fructose to 1&6, 1-kestopentaose. This paper provides structures of the various DP 3, 4, 5 and 6 fructan types produced by crested wheatgrass and provides suggested biosynthetic pathways for all major fructan linkage types present.