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Microbial communities of soils affected by long-term heavy metal contamination
Průchová, Pavla ; Kopecký, Jan (advisor) ; Matyska Lišková, Petra (referee)
This work is focused on microbial communities living in the soil affected by long-term exposure to heavy metals. The soil was sampled at two sites with different levels of contamination near Příbram. In the samples, respiration rate was measured in vitro after addition of carbon sources and at different levels of cadmium, one of the contaminating metals found in the soil. After the incubation with carbon sources, soil samples were collected for environmental DNA isolation. Gene coding for 16S rRNA in Actinobacteria was amplified from the environmental DNA samples and the amplicon composition was assessed by terminal restriction fragment length polymorphism analysis. The resulting profiles were used to compare actinobacterial communities in both groups of soil samples and in individual treatments. The analysis showed a clear distinction between the two sites differing in the contamination level and shifts in the community composition of various intesity depending on the added substrate.
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Natural sources and sinks of volatile chlorinated hydrocarbons in the spruce forest ecosystem
Štangelová, Pavla ; Tesařová, Eva (advisor) ; Pavlík, Milan (referee)
Biogeochemical cycle of chlorine, particularly the formation of organically bound chlorine is still not well understood. In continental ecosystems chlorides act as source of chlorine, and also as a stress factor. Chlorides originate from precipitation of marine cloud masses. Organically bound chlorine in the environment is formed naturally by biotical and abiotical way. The biotical factors are microorganisms, plants, soil enzymes and animals. Volatile chlorinated hydrocarbons (VOCl) represent one group of organically bound chlorines. Several volatile chlorinated hydrocarbons reacts with atmospheric ozone, consequently causing depletion of the ozone layer. The most important known terrestrial source of volatile chlorinated hydrocarbons is the spruce forest ecosystem. Chlorine in the soil can be transformed by microorganisms into organically bound chlorine or translocated by transpiration stream in plants, where they are also transformed enzymatically into organically bound chlorine, and both of them can be emitted into the atmosphere. Too large amounts of chloride can affect the physiological functions of plants. In this thesis experiments were designed for measuring the natural emissions of volatile halogenated hydrocarbons from plants and fungi, with various periods of incubation, and also to...
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Ecology of yeasts in forest soils
Mašínová, Tereza ; Baldrian, Petr (advisor) ; Marečková, Markéta (referee) ; Kolařík, Miroslav (referee)
Microbial communities inhabiting upper soil horizons represent an important component of forest ecosystems. However, despite the evidence that yeasts represent an integral part of topsoil fungal communities, their role in forest ecosystems received so far little attention. The aims of my PhD thesis were to describe yeast communities in soil and litter of a temperate forest using high- throughput sequencing of environmental DNA, identify dominant yeast species and to explore how the composition of yeast communities reflects the biotic and abiotic factors of the environment. I also aimed to isolate yeasts from forest topsoil, describe novel yeast taxa abundant according to the environmental DNA survey and screen representative isolates for the traits relevant to their involvement in organic matter transformation. I have demonstrated that in forest topsoil, yeasts represent a substantial proportion of fungal communities with higher relative abundance in soil than in litter. In litter, yeast communities differ significantly among beech, oak and spruce-dominated stands. Drivers of community assembly are probably more complex in soils and comprise the effects of soil chemistry and vegetation. Even though there are similarities in the response of the communities of yeasts and filamentous fungi to...
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Pyrosequencing analysis of fungal assemblages and the effect of ITS rDNA intragenomic variation on diversity estimates
Zelenka, Tomáš ; Kolařík, Miroslav (advisor) ; Větrovský, Tomáš (referee)
The ITS region of nuclear ribosomal DNA has recently become a frequently studied region for its use as a barcode marker. It is employed in environmental metagenomic analyses, the determination of fungi and in studies of fungal phylogenetics. In genomes, rDNA occurs in the form of large multicopy tandem arrays. Thus common Sanger sequencing leads to a consensus of many copies which in fact conceals most of the potential intragenomic variation. However 454 pyrosequencing reveals the sequence of single copies. Although it is believed that most of the variation among copies is reduced during a process called concerted evolution, some variation might still be conserved, including variation of non-functional pseudogenes. As a consequence, when using 454 pyrosequencing, we are not able to discriminate between this variation and real diversity. This could have a huge impact on the estimation of real diversity as well as on the correct assessment of pyrosequence studies. This thesis reviews current knowledge of intragenomic variation among fungi and summarizes some papers applying pyrosequencing in the research of fungal diversity. At the same time it indicates intragenomic variation as a potential cause of untrue diversity in diversity studies. Up until now there hasn't existed any experimental survey covering...
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Molecular biology and ecology of microbial decomposition of plant-derived biopolymers in forest ecosystems
Žifčáková, Lucia ; Baldrian, Petr (advisor) ; Uhlík, Ondřej (referee) ; Bárta, Jiří (referee)
The abilities of fungi and bacteria to degrade simple and complex carbon compounds derived from different sources, such as root exudates, litter, soil organic matter or fungal mycelium were studied in this dissertation. Knowledge of functional traits, especially degradation abilities of fungi and bacteria, are important for deciphering the black box of microbial functioning in topsoil and thus aiding in modeling and predicting future directions of microbial communities development in face of global changes. Among fungal cultures form culture collection representing strains with different taxonomy and ecophysiology, the ecophysiology of fungi was more important in manifestation of functional traits than taxonomy. Among bacterial isolates from the litter and soil of spruce forest, Acidobacteria were confirmed to express multiple decomposition enzymes in high rates in vitro and were also abundant and active degraders in acidic spruce forest soil. The expression of degradation capacities of both bacteria and fungi were further studied in situ in spruce forest topsoil, that represents an important environment due to the ubiquity of coniferous forests on the Northern hemisphere. There is an obvious gap of knowledge, when comes to our understanding of seasonal effect on microbial functioning, and this is...
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Clavarioid fungi: overview of their systematics and data on diversity in the Czech Republic
Matouš, Jan ; Holec, Jan (advisor) ; Tomšovský, Michal (referee)
In the first part of my bachelor thesis Clavariaceae family is characterized in historical, morphological and ecological perspective and three main genera Clavaria, Clavulinopsis and Ramariopsis with clavarioid and ramarioid morphology of fruit body are described. The second part surveys the development of their systematics and discusses the most important genera, which in certain phases of the system progress emerged in the Clavariaceae family. It also put emphasis on the characters that led the autors to their conclusions and on the development of the generic concept of the three mentioned clavarioid genera. The third part summarizes older and recent knowledge on the diversity of the three mentioned genera in the Czech Republic on the basis of the literature data. Species that have been found in the Czech Republic are listed and are briefly characterized from an ecological perspective. Powered by TCPDF (www.tcpdf.org)
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Modern fungicides and mechanism of their action
Zaleš, František ; Gabriel, Jiří (advisor) ; Ptáček, Petr (referee)
Fungicides are compounds, which are able to kill a fungi (they are therefore fungicidal), or they are able to slow or stop growth of a fungi (they are therefore fungistatic). Some fungicides also have insecticidal properties and can offer dual protection. This bachelor thesis is mainly dealing with fungicides, which are used to protect wood and wooden constructions from wood decaying fungi. Part of this bachelor thesis is a brief overview of wood decaying fungi and also an insight into the history of fungicides, but the main goal of this thesis is to offer a survey of currently used fungicides for wood protection against wood decaying fungi and also describe the mechanism of their action. Keywords: fungi, fungicides, buildings, general threat, wood decay, mode of action
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Fungal genetics, genome evolution and use of flow cytometry in study of DNA
Würtherlová, Tereza ; Kolařík, Miroslav (advisor) ; Kostovčík, Martin (referee)
The fungal genome is a dynamically changing structure. By its remodelling, the organism can respond to the environmental changes and develop itself. The genome expansion is often accompanied by transition to parasitic or mutualistic way of life. The genome expansion can be caused by the multiplication of some chromosomes (aneuploidisation), the whole genome duplication (polyploidisation) or the spreading of repetitive sequences. The impact of genome size to the ecology and life strategy of the organisms is more and more studied in recent years. In mycology, nevertheless, it escapes sufficient attention. The flow cytometry (FCM) is a modern and progressively developing method that enables to determine the genome size and estimate CG/AT base ratio. The combination of FCM with knowledge of the fungal ecology and forces that form the genome enable to discover a general trends of the evolutionary processes. My study summarises knowledge about the processes leading to changes in the size/structure of the fungal genome, the correlations with genome size and presents the principle of flow cytometry and its application in mycology.
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The influence of the dominant trees and grain substrate the composition of the microbial community studied by PLFA
Stachová, Sandra ; Frouz, Jan (advisor) ; Heděnec, Petr (referee)
The aim of the thesis was to analyze soil microbial communities of three ecologically different locations, about 25 years old, forestry reclaimed dumps in the Republic of Poland, namely dumps of brown coal mine Bełchatów and sand mines Piaseczno and Szczakowa. I evaluated the degree of dependence of structure and composition of these communities on various substrate grain sizes and the influence of the dominant tree species. These were stands of birch (Betula pendula), pine (Pinus silvestris), oak (Quercus robur) and alder (Alnus glutinosa). Analysis of soil microbial communities was made by evaluating specific phospholipid fatty acids (PLFA) of microorganisms. It is the most appropriate way to implement the relatively rapid analysis of large numbers of samples, since PLFA are easily extractable and act as biomarkers indicating the presence of a number of different microorganisms (fungi, G- and G + bacteria, Actinobacteria, etc.) and thus allowing a qualitative and quantitative assessment of whole microbial communities. PLFA analysis enables to detect a total concentration of PLFA only in living soil microbial biomass. I analyzed 66 soil samples, 33 from an Oe layer and 33 from an A layer, every in three replications, i.e. three replications were collected at each location below each tree...
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Taxonomy, diversity and clinical relevance of the genus Aspergillus
Hubka, Vít ; Kolařík, Miroslav (advisor) ; Labuda, Roman (referee) ; de Beer, Wilhelm (referee)
Aspergillus is a speciose genus encompassing nearly 400 species that has significant economic impacts on human health, the food industry, biotechnology and pharmacology. The research included in this thesis focuses on current issues related to the generic concept, subgeneric classification and species delimitation in Aspergillus. It addresses the need for revisions of several sections or species complexes. It provides novel information regarding etiology of aspergillosis as well as the antifungal susceptibilities of several less common opportunistic pathogens. The taxonomic section of the thesis contributes to the taxonomic stability and the new concept of the genus Aspergillus, which changed in response to the discontinuation of dual nomenclature in fungi. Sufficient arguments were collected (e.g., verification of monophyly, unifying phenotypic characters) for maintaining a broad concept of the genus and avoiding splitting it into several genera. All genera typified by sexual morphs and having Aspergillus asexual states were synonymized with Aspergillus and the appropriate names adopted; new combinations were made for teleomorphic species that lacked Aspergillus names. This thesis also contributed to infrageneric taxonomy of the genus via the proposal of four new sections in the subg. Circumdati,...
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