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Analysis of the macrozoobenthos community in flows with non-native fish and crustacean species
LORENC, Ondřej
The main objective of this bachelor thesis was to analyse and correctly determine the individual species of benthic organisms, that were present in the samples collected from the Jílovský (LJ) and Luční (LL) brooks, which are tributaries of the Elbe River. The sampling was carried out for two years (2018 and 2019). In each year, 12 samples were collected from the upper and lower reaches of these streams, both from the pools (P) and the stream reaches (R). The information was then used to assess various indicators of the macrozoobenthos community, namely the Sorenson similarity index, the Shannon Wiener diversity index and the saprobic index. The dominant group during both years for most samples was Diptera, with abundances ranging from 826 to 4228 ind. m-2 for individual sections. Their abundance was exceeded in only two cases out of eight. The first time was in 2018 in section LJ1, where many Oligochaeta (Enchytraeus sp.) were present, exactly 49942 ind. m-2, and the second time, also in 2018, in section LL2. Similarity according to the Sorenson index was found only once before comparing the upper sections with the lower sections in 2018 in the Jílovský Brook (70.97%). Diversity was mostly low, except in section LL2 in 2019 where medium diversity was found. Saprobic index values were higher in the lower reaches than in the upper reaches for both streams. It reached the highest value of 3.85 (polysaprobity) in the lower section of Luční Brook in 2018. The lowest value of the saprobic index was 1.9, which was reached in the upper section of Luční Brook in 2019. Results of diversity and saprobicity indicate an unnatural benthic condition in both streams, especially in sections closer to the confluence with the Elbe River. The macrozoobenthos community is strongly influenced by anthropogenic activities in these parts of both streams. One non-native species of macrozoobenthos, the Potamopyrgus antipodarum, was found in samples from both streams. In view of the condition of the macrozoobenthos communities in the Jílovský and Luční brooks, the main problem of these streams is the organic load caused by human activities.
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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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Genus Sicista (Mammalia, Rodentia, Zapodidae) in the Western Palearctics: diversity, phylogeny and paleobiogeography.
Lišková, Tereza ; Horáček, Ivan (advisor) ; Vohralík, Vladimír (referee)
The bachelor thesis surveys literary data on taxonomy, distribution, phylogeny and range history of the genus Sicista, one of the least known clade of Palearctic rodents. The genus composes a monotypic family Sminthidae, a basal branch of the superfamily Dipodoidea recorded since the late Eocene. Fourteen recent species are currenty distinguished. Most of them colonize small vicariant ranges distributed from East Asia to Central Europe with peak of species diversity in Central Asia and Caucasus regions. Also two taxa occupying large ranges (S.betulina, S.subtilis) including eastern parts of Central Europe rank among the rarest local specis throughout most of their ranges. The European fossil record (more than 150 Quaternary sites) indicate quite a more extensive distribution covering diverse regions of the Western Europe during the Pleistocene and the early Holocene. Yet, the species identity of many fossil records remain doubtful due to quite indistinct morphological differences among particular species. The discrimination criteria and range history in Central Europe are discussed in details with particular attention to the fossil record available from the Czech Republic and Slovakia. Key words: Sicista, phylogeny, range history, diversity, taxonomy, Western Palearctics
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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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Cytotoxicity and secondary metabolites of cyanobacteria
HROUZEK, Pavel
Cyanobacteria are well-known producers of secondary metabolites of different chemical structures and a wide range of biological functions. In the present thesis, the cytotoxic activity of cyanobacteria, originating from different habitats, was studied in order to reveal whether cytotoxicity is an environmentally dependent characteristic. In addition, the data were compared with the toxicity of these extracts to the model invertebrate Artemia salina. The obtained data suggest that cytotoxic cyanobacteria are favoured under some conditions and thus more frequent in particular localities. The majority of the studied extracts and fractions exhibited cytotoxitity to the Sp/2 cell line not accompanied by toxicity to A. salina. Moreover, in most of the strains with both activities to A. salina and Sp/2 cells the toxic effect was caused by an identical fraction. This result suggests that the toxic effect of the cyanobacterial secondary metabolites is mostly affecting basal cell metabolism rather than targeting specific organisms. In one of studied strains, Cylindrospermum sp. C24/1989, novel lipopeptides puwainaphycin F and G have been detected, isolated and their structure and biological effect have been characterized. Both of these structures interfere with eucaryotic membranes and cause a Ca2+ leakage into the cell. Subsequently, an enhanced tyrosine phosohorylation and relocalization of f-actin in the cell was observed. Lastly, the correlation between metabolite production and the reconstructed phylogeny was studied in planktonic Dolichospermopsis strains. Most of the detected compounds were found to be randomly disspersed across the reconstructed phylogeny and thus cannot be considered as good chemotaxonomic markers. This result also hampers the possible detection of toxic cyanobacteria by morphological methods or molecular detection based on the 16SrDNA gene.
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