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  • Author or Editor: B. Biró x
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Cadmium, nickel or zinc contaminated soils originating from a long-term heavy metal field experiment were used to assess the influence of those particular treatments on the coexistence of various Trichoderma species. The abundance of six indigenous Trichoderma spp. - T . atroviride , T . harzianum , T . pubescens , T . tomentosum , T . virens and T . viride - were studied 12 years after the application of Cd, Zn and Ni salts on four levels (0, 30, 90 and 270 mg·kg -1 ) in a calcareous chernozem soil. Trichoderma fungal colonies from the soil particles were estimated on selective media. The isolated strains were taxonomically characterized by microscopic visualization.  A reduced Trichoderma fungal colonization was found at the lower ratio of the studied metals. No colonization could be recorded in the case of Cd, and a slightly increased abundance at Ni and Zn metal salts at the highest 270 mg·kg -1 doses. The species composition of the fungi varied considerably in the contaminated samples as a function of the metals and the applied doses. Correlation analysis revealed that the population density of T . atroviride , T . harzianum , T . pubescens , T . viride was negatively affected by the available Cd concentration. The nickel content of the soil, however, correlated positively with the abundance of T . harzianum (r = 0.955) and T . virens (r = 0.964). In addition to this finding, the frequency of T . viride and T . tomentosum showed significant positive and negative correlation with the Zn treatment (r = 0.955; r = -0.965, respectively). Great differences between the correlation and partial correlation coefficients suggested that the heavy metals may alter not only the abundance of the fungi, but the interspecific relationships among the indigenous Trichoderma population, as well. This fact is considered to have further influence on some other biotic parameters and the soil functioning in heavy-metal-affected soils.

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A pot experiment was set up at the Experimental Farm of the Faculty of Horticultural Sciences of the Szent István University in 2001 investigating the revitalization effect of selected treatments on thermal-treated soils and other production substances. In the experiment 6 factors and 7 treatments were used, each in 4 replicates, using rape ( Brassica napus DC ) as test plant. During the time period of the experiment (29 May-17 August) continuous observations and measurements were conducted, plant and soil analyses - chemical and microbiological - were made to establish the main effects and results of the different treatments. These are discussed in the paper in detail. Although the soil-vitalization procedures were of great success, no treatment in the experiment had an extremely positive effect. Various additives, however could enhance the re-colonization processes significantly.  According to the basic factors (the soils or substrates) the best treatments were: the A1 (clay-pearl) additive and the C2, C3 factors (the medium and low temperature soil treatments).  Among the treatment combinations, treatments IV and VII were the best ( compost and compost + inocula addition). This fact shows that the compost in a good quality, and the compost enriched, compost extracted microbial inocula can play the most important role in the revitalization of thermal-treated soils. Manure addition and the manure + inocula treatment can also be used as a prominent treatment in the restoration, to increase the organic matter content and the microbial activity in soils. The single alga- and microbial inocula treatment was not successful permanently, therefore their use - without adding any parallel organic matter - cannot be recommended. Investigations of the soil microbial activity showed that the lowest temperature of thermal treatments had resulted a more effective revitalization. The clay-pearl additive increased the persistency and activity of the microbes in the soil. It was also obviously found that the organic additives with or without the microbial inoculations could be used potentially as the best soil revitalization treatments. 

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A pot experiment was designed to study the colonization of indigenous arbuscular mycorrhizal fungi (AMF) on barley ( Hordeum vulgare L.) host plant. Soils of the pots were collected from a long-term field microelement loading experiment on calcareous chernozem soil twelve years after 13 heavy metals (Al, As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sr and Zn) were applied once in four doses (0, 30, 90 and 270 mg element·kg -1 d.w.). The biomass production and element accumulation of the host plant, the various colonization values of the arbuscular mycorrhiza fungi (AMF) – such as colonization intensity (M %), arbusculum richness (A %) in the root system and the sporulation intensity (g -1 dry soil) in the rhizosphere – were measured. When considering the twelve-year adaptation process of the AM fungal populations at the various metal loads, a relatively balanced inside mycorrhiza colonization was found, suggesting the potentials for the selection of tolerant fungi in metal contaminated soils. The balanced infection intensity (M %) of the AM fungi and their common strategies with the host plant have resulted a nonsignificant shoot and root biomass production of barley in general. Mycorrhiza sporulation in the root system proved to be much variable and indicated the toxicity of metals and metal rates. Cd, Pb and Sr elements significantly reduced spore numbers, while a value of 34 spores·g -1 soil was counted in the case of Ni in comparison to the control’s 22 spores·g -1 soil value. Stress-defending strategies of the fungal–plant symbiosis, such as the increased arbusculum richness (A %) could be established for the Hg and Pb rates. In the case of Cd an increased root biomass production became a tool for stress alleviation and reduced the metal allocation towards the shoots. Mycorrhiza fungi are part of the common plant–microbe interactions and appropriate defending mechanisms in metal contaminated soils.

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The relationship between some soil physical-chemical characteristics, with more focus on the types of salt-specific anions and the colonisation parameters of the arbuscular mycorrhizal fungi (AMF) were examined on the most dominant halophytes, grown at four saline soils in Hungary. At site Z (Zám) mainly the chloride, at site Ny (Nyírõlapos) mainly the sulphate ions dominated in the soil samples, while at site A (Apajpuszta) and site Zsz (Zabszék) the carbonate anions were the most frequent. A large colonisation variability of the AM fungi were found in the four saline sites and the studied halophytes. Among the affecting soil-plant factors a strong host dependency was recorded with almost no mycorrhiza colonisation on Puccinellia limosa and the highest values at the Plantago maritima and Aster tripolium . As a function of the salt-levels a relative location of the halophytes could be found at each sites. The AMF colonisation intensity (M%) and functioning, measured as arbusculum richness (A%) was reduced with the overall increasing salinity, more particularly with the total cation-content of the soils. The deleterious effect of some other abiotic factors, i.e., the very poor or rich nutrient availability and the humus accumulation tended to be also negatively correlated by the mycorrhizal parameters.

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Abstract

The degree of soil pollutants in the Dunaújváros area has been monitored regularly at 10 sampling points of the town from the upper 0–20 cm and lower 20–40 cm layers of the soils. The quantity of some organic (PAH, TPH) and inorganic (toxic metal) pollutants were determined by GC-MS and ICP analyzation. Microbial status, such as the total cultivable bacteria (CFU) and total catabolic enzyme activity, measured by fluorescein diacetate analysis (FDA) were also estimated. The area of the industrial town could be divided into more and less contaminated regions, although the measured pollutants were far below the estimated permissible limits. However, at some of the more polluted soils even triple amounts of contaminants could be measured compared to the lesscontaminated sites. Among inorganics the Zn microelement reached the highest levels (average is about 100 mg·kg−1 soil), which could be related to the heavy industrial activity. A positive correlation appeared among the organic and inorganic pollutants and also between the pollutants and the measured enzymatic values. The enhanced FDA activity was found at the most contaminated sites preceding the potential “loss of function” on a long-term basis. The fast and reliable microbial parameter could be suggested as further regular monitoring tool.

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Regional habitat pattern of the Danube-Tisza Interfluve in Hungary II

The sand, the steppe and the riverine vegetation, degraded and regenerating habitats, regional habitat destruction

Authors: M. Biró, A. Révész, Zs. Molnár, F. Horváth and B. Czúcz

The increased endangerment and rapid devastation of the vegetation on the Danube-Tisza Interfluve are quite complex processes that can be approached from a manifold ways. One of the most important factors having influenced the vegetation in the recent past is the decline of the groundwater-level, the extent of which is well known and the reasons for that have been investigated for a long time. However, only few have studied its dramatic effect on the vegetation outside the local scale. In the first part of our bipartite article we discuss the regional habitat-pattern of the landscape, the background factors determining it, and the basic features of fen and alkali vegetation (Biró et al. 2007). In this second part, this will be completed by the sand, riverine and steppe vegetation and the data on habitat devastation on the regional scale. The analysis of the present habitat-pattern of the region was based on data of the actual (1996–2000) habitat map of Danube-Tisza Interfluve (Molnár et al. 2000, Biró et al. 2003) and on our experiences during the field survey. The quantitative analysis of the vegetation pattern was carried out considering the vegetation subregions. Our aim is to expose the actual state of the landscape, the vegetation and the rapid devastation of the natural habitats, by quantifying the current processes.Our results demonstrate that the extension of those habitats on the Danube-Tisza Interfluve that were not under cultivation in the 1980s has decreased drastically, by 40,074 ha (approx. 15%). The main reasons for grassland devastations are ploughing, afforestation, the invasion of shrubs and trees, the building in activity and the establishment of open water surfaces. The most serious decline in the recent past was observed in the case of fen vegetation: the decrease of its extension was estimated to be 10–11%. More than half of the habitats disappeared as a result of ploughing and grassland-devastation due to urbanisation (building in, development of infrastructure, etc.) was covered by fen vegetation, while about a quarter of them consisted of alkali habitats. Sand areas mostly decline because of the spontaneous invasion of alien species and afforestation, which led to the devastation of approx. 4% of the natural and disturbed sand vegetation. Astonishing is the fact that the total extension of the more-or-less disturbed or devastated habitats altogether comprise roughly half (49%) of the actually mapped vegetation patches of the Interfluve (137,908 ha). By summing up the areas of the most frequent habitat types of the vegetation subregions, it became evident that the grasslands, ploughed in the past 15 years, are among the first five most spacious habitat types in all subregions.

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The theory of âeœcodon-amino acid coevolutionâe? was first proposed by Woese in 1967. It suggests that there is a stereochemical matching - that is, affinity - between amino acids and certain of the base triplet sequences that code for those amino acids. We have constructed a Common Periodic Table of Codons and Amino Acids, where the Nucleic Acid Table showed perfect axial symmetry for codons and the corresponding Amino Acid Table also displayedperiodicity regarding the biochemical properties (charge and hydrophobicity) of the 20 amino acids and the position of the stop signals. The Table indicates that the middle (2 nd) amino acid in the codon has a prominent role in determining some of the structural features of the amino acids. The possibility that physical contact between codons and amino acids might exist was tested on restriction enzymes. Many recognition site-like sequences were found in the coding sequences of these enzymes and as many as 73 examples of codon-amino acid co-location were observed in the 7 known 3D structures (December 2003) of endonuclease-nucleic acid complexes. These results indicate that the smallest possible units of specific nucleic acid-protein interaction are indeed the stereochemically compatible codons and amino acids.

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Phytoremediation is an approach designed to extract excessive heavy metals from contaminated soils through plant uptake. Cadmium (Cd) is among the elements most toxic to living organisms. Health hazards associated with the lethal intake of Cd include renal (kidney) damage, anaemia, hypertension and liver damage. A greenhouse experiment was carried out with Indian mustard (Brassica juncea) grown on artificially spiked soil (100 μg Cd g−1) with EDTA (2 mmol kg−1 in 5 split doses), FYM, vermicompost (VC) and microbial inoculants (MI) such as Azotobacter sp. and Pseudomonas sp. The growth of Brassica juncea L. was better in soil amended with FYM or VC as compared to unamended Cd-polluted soil. Growth was slightly suppressed in EDTA-treated soil, whereas it was better after treatment with MI. The application of FYM and VC increased the dry matter yield of Indian mustard either alone or in combination with microbial inoculants, while that of EDTA caused a significant decrease in the biomass of Indian mustard. The application of microbial inoculants increased the dry matter yield of both the roots and shoots, but not significantly, because MI shows greater sensitivity towards cadmium. The maximum cadmium concentration was observed in the EDTA +MI treatment, but Cd uptake was maximum in the VC + MI treatment. The Cd concentration in the shoots increased by 120% in CdEDTA over the Cd100 treatment, followed by CdVC (65%) and CdFYM (42%) in the absence of microbial inoculants. The corresponding values in the presence of MI were 107, 51 and 37%, respectively. A similar trend was also observed in the roots in the order CdEDTA+M > CdVC+M > CdFYM+M>Cd100+M.MI caused an increase in Cd content of 5.5% in the roots and 4.1% in the shoots in the CdEDTA+M treatment compared with the CdEDTA treatment. FYM, VC and EDTA also increased Cd uptake significantly both in the shoots and roots with and without microbial inoculants.The results indicated that Vermicompost in combination with microbial inoculants is the best treatment for the phytoremediation of Cd-contaminated soil by Indian mustard, as revealed by the Cd uptake values in the shoots: CdVC+M (2265.7 μg/pot) followed by CdEDTA+M (2251.2 μg/pot), CdFYM+M (1485.7 μg/pot) and Cd100+M (993.1 μg/pot).

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A feeding experiment was conducted on northern pike, Esox lucius L. (123.6±33.3 g initial body weight) applying graded dietary fish oil supplementation resulting three dietary fat levels (without supplementation: 6.2% fat and 11.7, 17.4% fat levels with supplementations) in a recirculation system. Feed consumption, feed efficiency and protein utilization of pike was not affected by the treatment. Whole body lipid content analysis showed that the composition of pike was significantly affected by the increasing level of fish oil supplementation, although no relationship was detected between the dietary and the fillet lipid content, as well as the protein content of fish bodies. High docosahexaenoic acid (DHA, C22:6n-3) proportions were found in the muscle lipids (groups fed fish oil supplementation), as compared to the dietary fatty acid compositions suggesting that with dietary fish oil supplementation the dietary precursors (mainly EPA) enable pike to convert long chain highly unsaturated fatty acids, especially DHA; resulting high DHA: EPA ratios in the fillet.

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Authors: L. Biró, B. Rabin, A. Regöly-Mérei, K. Nagy, B. Pintér, E. Beretvás, E. Morava and M. Antal

The lack of data regarding dietary and lifestyle habits of Hungarian university students prompted us to undertake a cross-sectional pilot study of students of Semmelweis University, Budapest. A total of 264 students (78 males with mean age of 21.4±2.6 y and 186 females with a mean age of 21.2±2.6 y) were involved in the study. The questionnaires contained inquiries of energy and nutrient intake, use of vitamin and mineral supplements, food frequency, meal frequency and physical activity. Statistical analysis was carried out using SPSS for Windows 9.0. The energy, protein and fat intake was somewhat higher than the Hungarian Recommended Dietary Allowances (HRDA) (BIRÓ & LINDNER, 1999). Sodium intake was alarmingly high. Vitamin D consumption was inadequate. The intake of the members of vitamin B group with exception of B12 and niacin was insufficient. The daily consumption of milk, dairy products, fruits and vegetables was deficient. The meal pattern was unbalanced. Only 66% of males and 52% of females were involved in a regular physical activity. Our results suggest that nutrition should be introduced into the medical curriculum as a separate and full-fledged course of study.

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