|
|
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.
|
|
|
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.
|
|
|
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.
|
|
|
Soil microorganisms as controllers of methane emission from soils
Elhottová, Dana ; Němcová, Anna ; Chroňáková, Alica ; Šimek, Miloslav
The pilot study on functional microbial groups responsible for methanogenic and methanotrophic processes in soil of specific model ecosystem – the cattle overwintering pasture was given. The enrichment by methanogenic archaea was shown in soils strongly impacted due to cattle pasture. The increased methanogenic abundance was accompanied by increased abundance of methylotrophic bacteria. Nevertheless, the ratio of methylotrophic to methanogenic microorganisms was significantly higher in the control soils without cattle impact in comparison to the cattle-impacted soils.
|
|
|
Nitrogen and carbon transformation processes in soil in permanent grasslands - research in cattle overwintering area
Šimek, Miloslav ; Hynšt, Jaroslav ; Čuhel, Jiří ; Elhottová, Dana ; Chroňáková, Alica ; Němcová, Anna ; Jirout, Jiří ; Krištůfek, Václav
Agricultural soils represent a significant source of greenhouse gases (carbon dioxide, nitrous oxide and methane). Pasture soils and especially overwintering areas receive large amounts of nutrients as animal excrements. Together with other effects, this creates good conditions for high rates of nitrogen and carbon transformations, and also for substantial losses in the form of gaseous metabolites. This paper informs on research of a specific model ecosystem – the cattle overwintering area. Research is focused either on the structure of soil microbial community and on its activities including the formation of gases in, and their emission from the soil to atmosphere.
|
|
|
Quantification of key genes in nitrification and denitrification
Chroňáková, Alica ; Čuhel, Jiří ; Radl, V. ; Elhottová, Dana ; Šimek, Miloslav
The objective of the study was to explore the long-term effect of cattle grazing activities on abundance of nitrifying and denitrifying communities on overwintering area. The abundances of studied populations were determined using qPCR method and copy numbers of .i.amoA, nirS,./i. and .i.nirK./i. genes were quantified in spring and fall. High input of cattle urine and excrements with other animal activities had a significant impact on abundance of nitrifying and denitrifying bacteria, being higher in cattle impacted soils in comparison to control. Our data also showed that abundance of both bacterial communities reflected seasonal changes.
|
|
| |
guest ::
