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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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Culture Collection of Soil Actinomycetes in the Institute of Soil Biology BC ASCR, v.v.i. České Budějovice
Krištůfek, Václav ; Chroňáková, Alica ; Elhottová, Dana ; Petrásek, Jiří ; Němec, Jan
The Culture Collection of Actinomycetes in České Budějovice (CCACB) was established in 2006 that serves as a depository for cultures of soil actinomycetes. The cultures can be used for research, industrial applications, education and general scientific interest. Cultures are preserved mainly in glycerol or freeze-dried conserves. CCACB will offer strains of actinomycetes, namely streptomycetes (more than 900 cultures at the present moment), in catalogue of cultures www.upb.cas.cz, www.actinomycetes.cz.
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Detection of microorganisms in the soil using CARD-FISH (Catalyzed Reporter Deposition - Fluorescence in situ hybridization)
Krištůfek, Václav ; Kasalický, Vojtěch ; Chroňáková, Alica ; Elhottová, Dana ; Němec, Jan
CARD-FISH protocol (Catalyzed Reporter Deposition - Fluorescence in situ Hybridization) for detection of soil microbial community composition was successfully established in the Institute of Soil Biology. CARD-FISH is the relatively new molecular biology tool permitting to quantify distinct groups of microorganisms by hybridization of specific oligonucleotide probes. Compared to classic FISH-protocol the probe-attached enzyme amplifies the fluorescent signal and enables to detect nearly all microorganisms in soil or in organic compounds. As the first, we used this method to determine the bacterial community composition of a dated layer of guano-heap from Domica Cave (Slovak Carst National Park, Slovakia). We quantified the percentuel composition of Archaea, Eubacteria (.i.Planktomycetales, Verrucomicrobiales./i. included) and major bacterial groups (Actinobacteria, proteobacteria, .i.Cytophaga-Flavobacter./i.-Bacteroidetes, Sphingobacteria).
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Changes of microbial communities resulting from the passage through the earthworm gut
Němcová, Anna ; Pižl, Václav ; Elhottová, Dana
Selective effect of earthworm gut conditions is participating in the reduction or stimulation of individual microbial groups. In general, the passage through the earthworm digestive tract leads to an increase of total active microbial biomass. The numbers of cultivable bacteria present in earthworm gut are not shifted significantly in comparison with surrounding environment but their species richness changes. Usually some bacterial groups are partially changed during the passage. The long-lasting effect of the passage and animal excretion into the soil can involve the function of important microbial groups. The aim of this study was to summarize current knowledge about both quantitative and qualitative characteristics of the microflora connected with these significant representatives of soil macrofauna.
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The cultivation of bacteria originated in bat guano
Petrásek, Jiří ; Elhottová, Dana ; Krištůfek, Václav ; Kováč, L.
The bat guano represents an important source of organic matter in the oligotrophic caves. The high content of chitin from the remains of digested insect in bat diet causes the slow decomposition of the guano. The bat guano deposits can be auccumulated near the bat colonies during hundreds of years. The bat guano represents unique environment with specific conditions and appropriate composition of bacterial community. In this study, the bacterial communities of the guano from Domica and Ardovská Caves (NP Slovak Karst) were investigated using plate method with six different growing media. Total numbers of cultivable aerobic bacteria in guano were determined on the solid complex medium TSBA (Becton & Dickinson]. Total numbers of cultivable anaerobic bacteria were determined on the DifcoTM Anaerobic agar and blood agar (Schaedler agar with 5% sheep blood).
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Microarthropods and microbial participation in oak and beech litter decomposition
Farská, Jitka ; Jínová, Kristýna ; Jirout, Jiří ; Petrásek, Jiří ; Čápová, Lenka ; Rusek, Josef ; Krištůfek, Václav ; Elhottová, Dana ; Starý, Josef
The aim of our work was to describe the impact of a simulated vegetation zone shift to higher altitudes (i) on the quantity and quality of microarthropods and microbial communities, and (ii) on the decomposition rate of allochthonous leaf litter. In November 2002, 480 litterbags filled with oak or beech leaf litter were placed into spruce and beech forests (950 m a. s. l.) on Kleť Mt. (1083 m; Blanský les Protected Landscape Area, South Bohemia). Three different mesh sizes were used for certain soil biota exclusion: > 2 mm, 0.5 mm and 42 μm. Litterbags were sampled after 2, 4, 6, 12, 24 and 36 months of exposure in the field. Litter pH and moisture were determined in the laboratory immediately after retrieval. Soil microarthropods (Oribatida, Gamasida and Collembola) were extracted using Tullgren funnels. Soil bacteria and micromycetes were isolated using the dilution plate method and specific growth media.
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Nutrient and salinity effect on microbial processes in tropical wetlands
Černá, B. ; Elhottová, Dana ; Rejmánková, E. ; Šantrůčková, H.
Changes in microbial characteristics due to an increasing phosphorus loading were observed on wetland sediments in northern part of Belize. These primarily oligotrophic, phosphorus limited wetlands also substantially differed in salinity. The quantity and quality of organic material produced by autotrophs affect the composition and activity of sedimentary microflora and consequently P and N cycles. As effect of an increasing P loading the portion of autotrophs is changed from the predominance of cyanobacteria in oligotrophic wetland through predominance of .i.Eleocharis./i. sp. to predominace of .i.Typha./i. sp. in eutrophic wetland. There is presumption of the shift from P limitation to N limitation due to decrease in overgrowth of cyanobacteria and so decrease in N input by autotrophic N.sub.2./sub. fixation. The extent of the shift will depend on the size of internal N cycle and the ability of heterotrophic microflora, mainly nitrogen fixators, to afford sufficient amount of N.
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Archaea – the important part of soil microbial community
Němcová, Anna ; Elhottová, Dana
Archaea is a very old group of prokaryotic microorganisms distinguished by unique characteristics from other procaryotic representatives. Archaea represent the third discrete domain of life. The recent research focused on biology and ecology of Archaea has brought quite new and fascinating information about these microorganisms as well as about the life evolution in general. By virtue of application of recent molecular methods, it is apparent that archaeal habitat is not limited only to extreme environments but it is a distributed group coexisting with other microorganisms in common environments. The study of archaeal role in processes of C and N transformation connected with production and emission of greenhouse gases belongs to important problematic of recent soil biology. From a point of view of the evolutionary relations among soil organisms or interaction with other representatives of edafon the study of Archaea represents other important tasks of soil biology.
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Methods for study of soil fungal communities - application on soils disturbed by outdoor cattle husbandry
Jirout, Jiří ; Elhottová, Dana
Fungal organisms comprise a physiologically and genetically diverse group of organisms with the key role in soil ecosystems. However, dynamics, structure, diversity and biomass of populations of soil fungi remain unclear and unknown. Conventional methods in microbiology provide only a glimpse view on the fungal diversity, but the last 15 years have brought many technological advances in community profiling and cultivation independent approaches to studying soil microorganisms. Changes in fungal diversity associated with agricultural management may affect the soil fertility and stability, but the effect of the agricultural practices on fungal complex community is still unclear. Conventional and modern methods in soil microbial ecology were used for study of microbial communities at the pasture used as a cattle overwintering area. Soil environment at this site is relevantly disturbed by cattle impact.
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