Transformation of beech forest litter as a factor that triggers arsenic solubility in soils developed on historical mine dumps

Purpose

Soils that develop on the dumps in historical arsenic mining sites contain high concentrations of As thus constituting a serious environmental risk. This study was aimed to examine the changes in arsenic solubility in mine soils as induced by organic matter introduced with forest litter.

Materials and methods

Four large samples of initially developed soils were collected from the dumps remaining in former mining sites and were incubated for 90 days at various moistures: 80% of maximum water holding capacity and 100% (flooded conditions), with and without addition of beech forest litter (BL), 50 g/kg. Soils contained up to 5.0% As. Soil pore water was collected periodically with MacroRhizon suction samplers and examined on As, Mn, and Fe concentrations, pH, Eh, and dissolved organic carbon (DOC). The properties of dissolved organic matter were characterized by UV-VIS spectroscopic parameters A4/A6 and SUVA₂₅₄.

Results and discussion

Application of BL resulted in an intensive release of As from soils, particularly at 100% moisture. As concentrations in soil pore water increased strongly during the first 2 or 4 weeks of incubation and then started to decrease in all cases, except for one flooded soil. As was released particularly intensively from carbonate-containing soils. The mechanisms of As mobilization, including reductive dissolution of Mn and Fe oxides and the competition with DOC for sorption sites on the oxides, were discussed as related to soil properties. Pore water concentrations of DOC were increasing at the beginning of incubation and started to decrease after two or four weeks. Spectroscopic parameters of dissolved organic matter in ZS soils indicated increasing aromaticity and progress of humification.

Conclusions

Forest litter introduced to mine dump soils causes a mobilization of As into soil pore water. This effect, particularly strong in carbonate-rich soils, is apparently related to high concentrations of DOC and usually declines with time, which may be explained by the progress in humification. The relationships between DOC properties and As speciation in soil pore water should be dissected for better interpretation of experimental results.

     

Porcine theca cells produce immunoreactive beta-endorphin and change steroidogenesis in response to opioid agonist.

In earlier in vitro experiments opioids affected steroidogenesis in porcine luteal and granulosa cells. The present studies were undertaken to examine the effects of FK 33-824 (opioid agonist) alone or in combination with LH, PRL or naloxone (NAL, opioid antagonist) on steroidogenesis in cultured porcine theca cells. Moreover, we have tested beta-endorphin-like immunoreactivity (beta-END-LI) concentrations in culture media under control conditions and following treatments of theca cells with LH, PRL, progesterone (P4), oestradiol (E2) or testosterone (T). FK 33-824 and NAL significantly increased P4 release by theca cells and inhibited stimulatory effect of LH on this steroid output. PRL-induced P4 secretion from the cells was blunted only by FK 33-824. Secretion of androstenedione (A4) and T was essentially elevated in the presence of FK 33-824 and this potentiation of both androgen release was completely abolished by PRL. NAL blocked stimulatory effect of the opioid agonist only in case of T. Secretion of oestradiol and oestrone was completely free from the influence of both the opioid agonist and antagonist. Pig theca cells were able to produce beta-END-LI but none of tested hormones (LH, PRL, P4, E2 and T alone or in combination) significantly affected this production. In conclusion, these data indicate that porcine theca cells may produce beta-END-LI and change their steroidogenesis in response to opioid peptides.     

Factors influencing fruit size in the strawberry (Fragaria ananassa Duch.)

Summary Fruit size is one of the most important characteristics of highly productive strawberry cultivars. The aim of the experiments was to establish the factors responsible for the expression of this trait. The total yield of large fruits correlates closely with the total yield of all fruits and depends mainly on the mean fruit weight of all fruits. The position of fruits on the inflorescence influences the decline of fruit size to a larger extent in small-fruited clones than in the large-fruited ones. The size of the fruit is controlled by the dimension of the receptacle and number of achenes. The stimulating effects of achenes are quite different in various genotypes and the fruit weight per achene declines with the inferior blossom position. The large-fruited clones have bigger leaves, a larger photosynthetic area, and thicker petioles and flower stalks. Their cells are larger, which is common for the giant genotypes. The results suggest that there exists a possibility for indirect selection of fruit size on the basis of some additional parameters, which can be useful particularily in the years of unsuitable weather conditions.     

Immediate Impact of the Flood (Bohemia, August 2002) on Selected Soil Characteristics

In August 2002 extreme floods affected Bohemia a part of the Czech Republic, along Vltava and Labe rivers. After the flood had culminated, soil samples of arable and meadow soil (flooded and control-non-flooded) have been collected in the surroundings of the cities of ?eské Budějovice (CB, South Bohemia, the Vltava river, the upper flood stream) and Ústí nad Labem (UL, the Labe river, the lower flood stream). Different parameters of arable soils have been affected more significantly than those of meadow soils. Soil texture e.g. has been shifted from sandy loam to loam (CB) and clay loam (UL). Organic carbon, total phosphorus and nitrogen contents have been increased as well as the content of some hazardous elements such as arsenic. A shift of soil pH from 6.1 to 4.8 has been noticed in CB and an opposite one from 5.1 to 7.1 was measured in UL. Available phosphorus decreased in CB by 56% while a four-fold increase was measured in UL. Chlorinated organic pesticides level was significantly reduced, but that of polycyclic aromatic hydrocarbons (PAH) increased up to the maximum values of legal limits. The UL arable soil also became heavily contaminated by PAH. The CB arable soil demonstrated high microbial activity, while UL arable soil suffered under stress conditions in this respect. The flooded meadow soils became covered with a layer of drifted soil sediment, which retained enhanced content of the PAH's different hazardous elements, and, in addition, the soil aeration was reduced.     

Mosses as bioindicators of heavy metal pollution in polish national parks

The concentrations of heavy metals (Cd, Co, Cr, Ni, Cu, Ph, Zn, Mn, Fe) and other elements (Mg, Na, K, Ca) were determined in the samples of Pleurozium schreberi and Hylocomium splendens from 12 Polish national parks. The significant differences in the concentrations of all heavy metals between particular parks were found. The lowest concentrations of these metals were recorded in the mosses from the national parks in northern Poland, the highest in southern Poland. Significant differences in the heavy metals contents of the mosses between central and peripheral park areas, between green and brown parts of mosses, as well as between moss species were also found.     

Fatty acid composition of various ectomycorrhizal fungi and ectomycorrhizas of Norway spruce

Whole cell fatty acid (WCFA) compositions of three different structures of ectomycorrhizal (ECM) fungi: sporocarps, pure culture mycelia and ectomycorrhizas were analysed to evaluate the potential use of fatty acid profiles as biomarkers for ECM fungi and ectomycorrhiza-associated bacteria. Sporocarps of Amanita muscaria, Amanita rubescens, Lactarius rufus, Lactarius thejogalus, Leccinum scabrum, Paxillus involutus, Russula foetens, Russula rosea, Russula vesca, Suillus grevillei, Tylopilus felleus, Xerocomus badius, Xerocomus subtomentosus, pure cultures of A. muscaria, P. involutus, X. badius, X. subtomentosus, Suillus bovinus Suillus luteus and seven ectomycorrhizal morphotypes of Norway spruce were examined. Our results revealed species-specific composition of fatty acids of fungal sporocarps and pure culture mycelia. Ectomycorrhizal morphotypes distinguished and identified by morphological and molecular methods (PCR-RLFP and sequencing) created specific fatty acid profiles. The dominating fatty acids in pure cultures and sporocarps were 18:2ω6,9, 18:1ω9 and 16:0, whereas ectomycorrhizas also contained plant and bacterial specific fatty acids. Especially, fatty acids specific to Gram-positive bacteria 15:0 anteiso and 17:0 anteiso were present in relatively high amounts and suggested that these bacteria are dominating in the examined Norway spruce mycorrhizosphere. In conclusion, our results show that fatty acid based methods can be useful in studies of ectomycorrhizal fungi, both as a quick method for differentiation of fungal species and also in studies of mycorrhiza-associated microorganisms in the field.     

Growth factor and cytokine interactions in myogenesis. Part II. Expression of IGF binding proteins and protein kinases essential for myogenesis in mouse C2C12 myogenic cells exposed to TNF-alpha and IFN-gamma

The aim of the study was to examine potential interactions among IGF-I and proinflammatory cytokines, TNF-alpha and IFN-gamma, in the regulation of local IGF-I bioavailability and cellular proteins mediating myogenic signals. We investigated levels of IGFBP-4, -5, -6, protein kinase Czeta (PKC zeta), p38 and extracellular signal-regulated kinase (ERK1/2) in differentiating mouse C2C12 myoblasts. IGF-I significantly stimulated expression of IGFBP-5. TNF-alpha and IFN-gamma attenuated the expression of IGFBP-4 and -6 under basal conditions and in the presence of IGF-I, and inhibited IGF-I-induced IGFBP-5 expression during 5-day myogenesis. TNF-alpha and IFN-gamma markedly attenuated p38 expression in the presence of IGF-I on the 5th day of myogenesis. When combined with IGF-I the cytokines exerted opposite effects on the PKC zeta level, i.e. TNF-alpha caused an increase, whereas IFN-gamma reduced the cellular content of this kinase. Exposition of C2C12 myoblasts to IGF-I or cytokines led to the stimulation of ERK1/2 phosphorylation; however, both TNF-alpha and IFN-gamma exerted an inhibitory effect on the activation of ERK1/2 in myoblasts cultured in the presence of IGF-I. We concluded as follows: i) TNF-alpha and IFN-gamma present in the extracellular environment of differentiating C2C12 myoblasts can alter the local bioavailability of IGF-I by inhibiting the expression of IGFBP-4, -5, and -6, ii) the decrease in p38 expression and ERK1/2 phosphorylation in C2C12 myoblasts exposed to cytokines can lead to disturbances in IGF-I-regulated myogenesis.     

The effect of diets supplemented with fish broth and fish oil on the health of weaners

The aim of this study was to determine the effect of fish-based feed materials, as a source of readily available protein contained in fish broth and essential polyunsaturated fatty acids (PUFAs) found in fish oil, on the health of piglets and rearing results. The experiment was conducted on a commercial pig fattening farm. The study involved a total of 80 weaners with an approximate body weight of 15 kg. The experiment was carried out over a period of 40 days. Feed samples were subjected to laboratory analyses. Blood samples were collected from experimental group animals to determine serum biochemical and immunological parameters. The body weight gains of weaners, mortality rates and average feed intake per animal were calculated for the entire experimental period. The addition of fish broth and fish oil significantly improved the n3:n6 fatty acid ratio in diets. The presence of EPA and DHA in the experimental diet could have had a positive health effect on piglets, comparable with that exerted by therapeutic doses of zinc often administered to pigs of this age group. During the experiment, feed conversion ratio (FCR) gain was considerably reduced in the experimental group, with similar daily gains in the control and experimental group.     

New natural host plants of ‘Candidatus Phytoplasma pini’ in Poland and the Czech Republic

The presence of phytoplasmas in seven coniferous plant species (Abies procera, Pinus banksiana, P. mugo, P. nigra, P. sylvestris, P. tabuliformis and Tsuga canadensis) was demonstrated using nested PCR with the primer pairs P1/P7 followed by R16F2n/R16R2. The phytoplasmas were detected in pine trees with witches’ broom symptoms growing in natural forest ecosystems and also in plants propagated from witches’ brooms. Identification of phytoplasmas was done using restriction fragment length polymorphism analysis (RFLP) of the 16S rDNA gene fragment with AluI, MseI and RsaI endonucleases. All samples showed RFLP patterns similar to the theoretical pattern of ‘Candidatus Phytoplasma pini’, based on the sequence of the reference isolate Pin127S. Nested PCR‐amplified products, obtained with primers R16F2n/R16R2, were sequenced. Comparison of the 16S rDNAs obtained revealed high (99·8–100%) nucleotide sequence identity between the phytoplasma isolates. The isolates were also closely related to four other phytoplasma isolates found in pine trees previously. Based on the results of RFLP and sequence analyses, the phytoplasma isolates tested were classified as members of the ‘Candidatus Phytoplasma pini’, group 16SrXXI.     

Phosphorus use Efficiency of Safflower (Carthamus tinctorius L.) and Sunflower (Helianthus annuus L.)

This study comparatively evaluates phosphorus (P) use efficiency of safflower and sunflower in view of identifying low input oil crops. Sunflower accumulated more P than safflower at all equivalent P supplies. Sunflower was more efficient at their best P supplies to utilize absorbed P than safflower in terms of efficiency ratio and utilization index. Yield response curves interpreting the functional relationship between nutrient supply and yield using Michaelis-Menten equation indicate that sunflower is less sensitive to inadequate P supply and thus more P-efficient than safflower with respect to yield, as the term ‘Km’ is lower for sunflower. The minimal P amount per pot required to trigger yield formation (term ‘Cmin’) was lower in sunflower than safflower. Harvest Index in sunflower out-yielded that of safflower at all P supplies. Critical deficiency contents of sunflower were lower than that for safflower. It can be concluded that safflower cannot be considered as low-input crop.