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Microbial degradation of 17alfa-ethinylestradiol and bisphenol A
Křesinová, Zdena ; Svobodová, Kateřina ; Moeder, M. ; Cajthaml, Tomáš
17ethinylestradiol (EE2) and bisphenol A (BA) are endocrine disrupting compounds (ED). ED have a negative influence on animals and human hormonal systems animals, and thus they are serious envronmental contaminants. This work was focused on biodegradtion of EE2 and BA using 8 white rot fungi strains in liquid media. Pleurotus ostreatus, Pycnoporus cinnabarinus and Irpex lacteus were able to remove both ED under detection limit (initial concetration was 10 ppm) during the first three days of cultivation. In contrary, Phanerochaete chrysosporium was not able to degrade both ED durin 2 weaks long cultivation
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Enzyme-catalysed processes in the spoil heaps after brown coal mining: effects of site age, vegetation and seasonality
Baldrian, Petr ; Šnajdr, Jaroslav ; Valášková, Vendula ; Urbanová, Michaela ; Voříšková, Jana ; Popelářová, Petra ; Herinková, Jana ; Cajthaml, Tomáš ; Frouz, Jan
Enzyme-catalysed processes in the spoil heaps after brown coal mining are affected by site age, vegetation composition and seasonality
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N.sub.2./sub.O and N.sub.2./sub. emissions, denitrification activity and the size of the denitrifying community in a pasture soil – what is the role of pH?
Čuhel, Jiří ; Šimek, Miloslav ; Laughlin, R.J. ; Chéneby, D. ; Bru, D. ; Philippot, L.
Denitrification and subsequent N emissions are significantly influenced by soil pH. Nevertheless, it is not clear, whether pH controls denitrification only due to the influence on kinetics of denitrification enzymes or also due to the different structure of denitrifiers. The objective of the present study was to compare results from N gas emissions and N.sub.2./sub.O molar ratio from soils with artificially changed pH, with those obtained from potential denitrification, and to find out whether there is a relationship between N fluxes and abundance of denitrifiers. The experimental site was located in a grassland area at Borová Farm near Český Krumlov, Czech Republic, and consisted of 12 plots (3x3 m) amended with KOH solution (pH alkaline), H.sub.2./sub.SO.sub.4./sub. solution (pH acidic) or with no amendments (pH natural). The .sup.15./sup.N gas flux method was used to quantify emissions of N.sub.2./sub.O and N.sub.2./sub. in situ at intervals over 74 H.
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Symptomes of nitrogen excess in soil
Hynšt, Jaroslav ; Šimek, Miloslav
Nitrogen cycling is one of the most important processes on the Earth. Most of N transformations run in soil. Nitrogen usually enters the soil as occasional input in concentrated forms which means that it is often in excess or in deficit. However, deficit and excess of N have different value in different soils and ecosystems. For example, amount of N which causes significant impact on ecosystem of spruce forest is insufficient for the maize field. This suggests, that the amount of N in soil must be evaluated in context of the whole ecosystem. In N-limited ecosystems, most of N is stored in plant biomass and litter characterized by slow transformations. Productivity of ecosystem is low, but N is utilized with high efficiency. On the other hand, in conditions of high availability of N, losses take place. These differences are reflected in content of different fractions of soluble N in soil and different rates of their transformations.
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Soil micromycetes - the potential source of N.sub.2./sub.O in soils
Jirout, Jiří ; Šimek, Miloslav ; Elhottová, Dana
The aim of this paper is to summarize knowledge on potential production of N.sub.2./sub.O by fungi. The processes involved in the global nitrogen cycle are suggested to have an important role in the global environmental changes. Nitrification and denitrification processes cotribute to the production of N.sub.2./sub.O, which belongs to the group of highly active greenhouse gases. Denitrification - the successive reduction of nitrate to N.sub.2./sub. - was supposed to occur only in prokaryotes, but recently the evidence for dissimilation of nitrates and formation of nitrogen oxides and N.sub.2./sub. was reported also in fungi. N.sub.2./sub.O of fungal origin is formed from nitrate or nitrite by reduction under anaerobic or microaerobic conditions. Since fungi showed the capability to use denitrification and oxygen respiration simultaneously under various pO.sub.2./sub. conditions, the N.sub.2./sub.O production by fungi is expected in a wide range of soils with different aeration status.
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