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Diversity of green algae identified as lichen photobionts
Vaiglová, Zuzana ; Škaloud, Pavel (advisor) ; Štifterová, Anna (referee)
This thesis is focused on green algae, which have been recorded as lichen photobionts. The thesis consists of description of genera from the green algal from classes Ulvophyceae, Trebouxiophyceae and Chlorophyceae. I focused on phylogenetics position of genera, I define their morphology and I summarize their participation in lichen symbiotic relationships. I compare evidences based on the traditional morphological methods and modern molecular data. The following genera can be stated to uncertainly represent lichen photobionts: Trentepohlia, Cephaleuros, Phycopeltis and Dilabifilum from the class Ulvophyceae, and Dictyochloropsis, Chloroidium, Elliptochloris, Coccomyxa, Diplosphaera, Auxenochlorella, Myrmecia, Asterochloris, Trebouxia, Coccobotrys and Leptosira from the class Trebouxiophyceae. The genera Chlorella and Stichococcus are morphologically poorly defined, but they are commonly reported as lichen photobionts. Prasiola associates with the mycobiont, but the identity of their partnership is not certainly defined. The lichen symbiosis of genera Parachloroidium, Pseudochlorella and Gloeocystis has not been confirmed by molecular methods, so far. Key words photobiont, lichen, green algae, Chlorophyta, diversity, phylogeny, Trebouxiophyceae
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Auxin transport in algae
Skokan, Roman ; Petrášek, Jan (advisor) ; Bíšová, Kateřina (referee)
Phytohormone auxin plays an important role in regulating plant development. Directional (polar) cell-to-cell auxin transport creates auxin gradients within plant tissues, which trigger a specific developmental response. The vast majority of available data concerns angiosperms. Lower land plants have been much less explored in this regard, but the important auxin-related mechanisms (including polar auxin transport) are already present in mosses. To uncover the origins of auxin action, one must focus on green algae, especially of clade Streptophyta, which are the direct ancestors of all land plants. In this study, the possible effects of auxins, both native and synthetic, were investigated on two algae: basal, unicellular Chlorella lobophora and advanced, filamentous Spirogyra sp. The latter received comparably more attention, since it belongs to a clade now acknowledged as a sister group to land plants. Chlorella lobophora culture growth was irresponsive to synthetic auxin NAA. The average Spirogyra sp. cell length was, however, changed by auxins at high concentrations. By conducting accumulation assays of radioactively labelled auxins and HPLC analysis, auxin metabolism and transport was investigated in Spirogyra sp. This alga was able to metabolize the plant-native IAA, but not synthetic auxins...
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Molecular diversity and species concept of subaerial green alga Trentepohlia (Ulvophyceae, Chlorophyta)
Šafránková, Michala ; Škaloud, Pavel (advisor) ; Štifterová, Anna (referee)
This Bachelor thesis discusses green subaerial algae of the genus Trentepohlia (Ulvophyceae, Chlorophyta). Firstly, I focus on general description of the family Trentepohliaceae and the genus Trentepohlia, especially on morphology, ultrastructure and reproduction. Secondly, I summarize the knowledge of the literature available about the species of the genus Trentepohlia living in the Czech Republic. I also concern with the symbiotic relationship of these algae with other organisms and with some curiosities of their growth leading to ecological and other important consequences. Finally, in this thesis I introduce the issues of the species delimitation using traditional morphological methods in contrast to molecular approaches. There are several facts resulting from this thesis. The genus Trentepohlia is a green alga of the Chlorophyta lineage curious in some aspects, mostly due to presence of some structures among the cells (such as plasmodesmatas, MLS, carotenoids, etc.). There is also a problem of determination of individual species. For almost two hundred years, this problem has been solved by use of morphological features. However, molecular methods are often in contrast to these traditional methods. Therefore, reorganization on a genus level is essential, based on the discovery of...
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Cryptic and pseudocryptic diversity of conjugating green algae (Zygnematophyceae)
Kupčíková, Eva ; Šťastný, Jan (advisor) ; Škaloud, Pavel (referee)
This bachelor thesis summarizes the most commonly used species concepts in the class Zygnematophyceae. This group of algae and the molecular markers used in the zygnematophytes' molecular phylogeny will be presented in this thesis. Zygnematophytes have unicellular or multicellular forms and they generally occur in freshwater habitats. Desmids are useful as indicators of water quality and they are also used for scoring of conservation value. Therefore it is important to have the species well defined. The confusion in defining of desmid species was caused by often very variable morphology. Some authors had different opinions on the classifying of desmid species and theirs subunits. The combination of molecular phylogeny, electron microscopy and geometric morphometrics was used in revealing of (pseudo)cryptic species in the genera Micrasterias or Xanthidium. The geometic morphometrics was helpful for finding of important details for distinguishing of particular pseudocryptic species. Key words: cryptic and pseudocryptic diversity, conjugation, desmids, Micrasterias, Euastrum, Xanthidium, molecular phylogeny, taxonomy, geometric morphometrics, biogeography, green algae
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Autotrophic microbial communities on needles of gymnosperms
Nováková, Radka ; Neustupa, Jiří (advisor) ; Škaloud, Pavel (referee)
This bachelor thesis summarizes available data on autotrophic microbial communities on needles of gymnosperms. This new phenomenon has been observed since 1980'. In my thesis the composition of these communities is described. In addition, their seasonal development, the correlation of species and abundance data with air pollution (mostly nitrogen and sulphur concentrations) are also referred. Except bioindication studies that used these epiphytic communities, similar papers using lichens were also included. The thesis also contains a chapter with detailed description of three most frequent green algae species occurring on needles. In my own work, relationship between epiphytic quantitave parameters of needle-inhabiting communities (thickness, cover, algae amount) of English Yew (Taxus baccata L.) were analyzed in relation to the air pollution data in Prague.
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Spoil heap toxicity and possibilities for remediation
Venclovská, Lenka ; Frouz, Jan (advisor) ; Lukavský, Jaromír (referee)
The content of this diploma thesis is to verify of possibilities for remediation spoil heap toxicity in Sokolov area, by the help of creating biological crusts. The main question of this work is the possibility of using algae to create biological crust on toxical substrates, which could improve the properties of substrates and contribute to the acceleration of succession. The correctness of this theory was tested using two tests on toxic soils in spoil heaps near Sokolov. In the first test (laboratory test) have been chosen two of the soils and the higher plants, in most cases, even did not germinate. That is why we decided to verify the second option to create biological crust in these phytotoxic soils. Therefore we applied selected kinds of algae in the field, some areas were liming, and the field has been monitoring and sampling during next three years. The results show that the application of dolomitic limestone does not affect progress of biological crusts. The result of the fluorescent microscopy clearly shows, that Klebsormidium algae was the only one of the tested algae, which survived and progressed compact visible crusts.
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Adhesion of microalgae Chlorella vulgaris to solid surfaces
Širmerová, Marcela ; Vymazal, Jan (advisor) ; Mojmír, Mojmír (referee)
Although adhesion of bacteria and yeast have been extensively studied by a wide range of experimental and theoretical approaches, significantly less attention has been focused on microalgal adhesion to solid materials. Therefore this doctoral thesis is focused on physico-chemical aspects of microalgal adhesion. The results are based on experimental characterization of surface properties of both microalgae and solids by contact angle and zeta potential measurements. These data were subsequently used in modeling the surface interactions (thermodynamic, classical and extended DLVO models) resulting in quantitative prediction of the interaction intensities. Finally, the model predictions are compared with experimental adhesion tests of microalgae onto model solids in order to identify the physico-chemical forces governing the microalgae-solid interaction. The model solids were prepared in order to cover a wide range of properties (hydrophobicity, surface charge). The results revealed that in low ionic strength environment the adhesion was influenced mostly by electrostatic attraction/repulsion between surfaces, while with increasing ionic strength grew the importance of apolar (hydrophobic) interactions. Among tested materials the highest adhesion of Chlorella vulgaris cells was observed to (3-aminopropyl)triethoxysilane modified glass (APTES glass) mimicking the surface properties of stainless steel. The impact of solid surface properties on the degree of colonization by microlagae was statistically more significant than the influence of culture medium composition on cell surface of Chlorella vulgaris.
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The possibilities of green algae removal from concrete structures
Cochlárová, Milena ; Ptáček, Petr (referee) ; Opravil, Tomáš (advisor)
This master´s thesis deals with the suppression of algal growth on concrete structures. The subject of the work is to design and coatings their own structural concretes containing protective element in order to inhibit the growth of algae. As the coating are tested commercially avaiable and newly created systems. Testing systems are based on the portland cement and chelates of metal (Cu, Ni, Co, Mn, Zn, Al).
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Determination of optimal conditions for cell growth and accumulation of storage lipids of the alga Trachydiscus minutus
ONDREJMIŠKOVÁ, Kamila
Algae are becoming a strategic source of fuels, food, feedstocks, and biologically active compounds. Algal lipids are among the most promising potential products. The yellow-green alga Trachydiscus minutus (class Eustigmatophyceae) is unicellular freshwater alga accumulating lipids as its storage reserves. The influence of various growth média, temperature and light intensity on the growth and accumulation of storage lipids of alga Trachydiscus minutus was studied. The optimal growth conditions were determined. Storage lipids were quantitatively determined fluorometrically. Accumulation of lipids was monitored by fluorescence microscopy.
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A taxonomy of the genus \kur{Stigeoclonium} in the Czech Republic
CAISOVÁ, Lenka
The genus Stigeoclonium is taxonomically very problematic. The relationships between species of this genus are very little known. There are only a few studies that deal with only morphological revision of the genus Stigeoclonium. Hovewer, up to now no phylogenetic analysis of this genus exists. This study summarizes the knowledge about the genus Stigeoclonim in the Czech Republic and shows the first phylogenetic analysis of this genus.
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