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Taxonomic position, phylogenetic relationships and metal resistance of green algae dominating in phytoplankton of two acid lakes
Barcyte, Dovile ; Nedbalová, Linda (advisor) ; Hašler, Petr (referee)
The aim of this diploma thesis was to reveal the taxonomic position and phylogenetic relationships of the dominant planktonic algae in two acid metal-rich lakes (Hromnice Lake and Plešné Lake, Czech Republic) and to compare these isolates with other closely related strains with the focus on the tolerance to various toxic metals (Cr, Al, Cu, Mn, Zn, Hg). The phylogenetic analyses showed that both strains belong to species Coccomyxa simplex. It was the first evidence that specifically this species is capable to become the dominant phytoplankton alga in the extreme environment of acid lakes with increased supply of phosphorus. Based on 18S rDNA analysis, four independent phylogenetic lineages were revealed within the genus Coccomyxa with three of them containing isolates from acid freshwaters. Furthermore, new strains of the recently described species Coccomyxa polymorpha were found growing in various chemical solutions. The toxicity test revealed that Coccomyxa simplex strains isolated from Hromnice and Plešné lakes did not show any peculiar resistance to increased metal concentrations. A significantly strain-specific response was recorded in case of aluminum, however, it was not related to the concentration of this metal in the original habitat. The ability to thrive in extreme habitats is probably...
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Specific water properties of pit lakes in the Czech Republic
Hrdinka, Tomáš ; Janský, Bohumír (advisor) ; Benešová, Libuše (referee) ; Herber, Vladimír (referee)
Anthropogenic lakes constitute a significant part of the Czech countryside water component which has not been given sufficient attention so far. The presented thesis deals with the assessment of variability of physico-chemical properties of water in 30 selected pit lakes in order to identify specific features associated with quarrying of different mineral raw materials, basin morphometry and trophic level of the lakes affecting the quality of accumulated water. In the second part of the thesis the author deals with the comprehensive limnological study of the Hromnické Lake with extreme water chemism resulting from excavation of pyritic shales and focuses on the phenomenon of meromixis especially. The results are based on the evaluation of physical properties of water in the lake vertical profile (temperature, conductivity, dissolved oxygen, pH, transparency and colour) and chemical analyzes of water samples collected from the surface and bottom of the lakes during the four seasons in 2003-07 (determination of Ca, Mg, Na, K, Nammon., NO3 - , SO4 2- , Cl- and alkalinity), including determination of chlorophyll-a. In the case study of the Hromnické Lake conducted in 2010-11, the analysis of hydrological regime of the lake, determination of PO4 3- , TOC, selected metals (Fe, Mn, Al, Zn, Ni, Cu, Co,...
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