A5070919558- Aquatic Ecosystems and Phytoplankton Dynamics
- Marine and coastal ecosystems
- Microbial Community Ecology and Physiology
- Aquatic Invertebrate Ecology and Behavior
- Fish Ecology and Management Studies
- Plant and Biological Electrophysiology Studies
- Environmental Toxicology and Ecotoxicology
- Protist diversity and phylogeny
- Soil and Water Nutrient Dynamics
- Freshwater macroinvertebrate diversity and ecology
- Aquaculture Nutrition and Growth
- Groundwater and Isotope Geochemistry
- Integrated Water Resources Management
- Groundwater flow and contamination studies
- Coastal wetland ecosystem dynamics
- Plant Molecular Biology Research
- Water resources management and optimization
- Aquaculture disease management and microbiota
- Botany and Plant Ecology Studies
- Environmental Science and Water Management
- Marine Bivalve and Aquaculture Studies
- Mine drainage and remediation techniques
- Wastewater Treatment and Nitrogen Removal
- Peatlands and Wetlands Ecology
- Light effects on plants
Silesian University in Opava
2025
Czech Academy of Sciences, Institute of Physics
2025
University of South Bohemia in České Budějovice
2014-2024
Institute of Hydrobiology, Biology Centre, Academy of Sciences of the Czech Republic
2014-2024
Czech Academy of Sciences, Biology Centre
2014-2024
Czech Academy of Sciences
1996-2022
Sewanee: The University of the South
1999-2014
Czech Academy of Sciences, Institute of Botany
2011
Universität Innsbruck
2007
Hydrobiological Institute
2001-2007
We investigated net growth rates of distinct bacterioplankton groups and heterotrophic nanoflagellate (HNF) communities in relation to phosphorus availability by analysing eight situ manipulation experiments, conducted between 1997 2003, the canyon-shaped Rímov reservoir (Czech Republic). Water samples were size-fractionated incubated dialysis bags at sampling site or transplanted into an area reservoir, which differed limitation (range soluble reactive concentrations--SRP, 0.7-96 microg...
In a two-stage continuous-flow system, we studied the impacts of different protozoan feeding modes on morphology and taxonomic structure mixed bacterial consortia, which were utilizing organic carbon released by pure culture Rhodomonas sp. grown inorganic medium in first stage system. Two three second stages operated parallel inoculated bacterivorous flagellate, Bodo saltans, an algivorous ciliate, Urotricha furcata, respectively. The third vessel served as control. two experiments, where...
We studied predator-induced changes within a slowly growing mixed microbial assemblage that was sustained by algal exudates in continuous cultivation system. In situ hybridization with fluorescent monolabeled oligonucleotide probes used for tentative community analysis. This method also allowed us to quantify the proportions of predators ingested bacteria different taxonomic groups. addition, we determined grazing rates on fluorescently labelled prey. Bacteria belonging alpha and beta...
ABSTRACT We investigated whether individual populations of freshwater bacteria in mixed experimental communities may exhibit specific responses to the presence different bacterivorous protists. In two successive experiments, a two-stage continuous cultivation system was inoculated with nonaxenic batch cultures cryptophyte Cryptomonas sp. Algal exudates provided sole source organic carbon for growth accompanying microflora. The dynamics several 16S rRNA-defined bacterial were followed...
Using oligonucleotide probes for Eubacteria and four eubacterial subgroups, we monitored changes in bacterial community composition (BCC) with different degrees of grazing pressure, as follows: unfiltered water (UNF, all bacterivores present); <20 μm (bacteria, heterotrophic nanoflagellates [HNF], small ciliates); <5 (bacteria HNF only); <1 or <0.8 only), incubated dialysis bags. Experiments were conducted the Rimov Reservoir (South Bohemia) during clear‐water phase (experiment...
Abstract Despite the importance of shallow lakes worldwide, knowledge microbial components, base their food webs, remains scarce. To close this gap, we investigated planktonic in particular protistan bacterivory (for both ciliates and heterotrophic nanoflagellates [HNF]), 10 hypertrophic fishponds South Bohemia (Czech Republic). We used fluorescently labeled bacteria as tracers to estimate how abundant populations (4–25 × 3 HNF mL −1 55–770 ) contribute total bacterial mortality....
AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 18:235-246 (1999) - doi:10.3354/ame018235 Predator-induced changes of bacterial size-structure and productivity studied on an experimental microbial community Thomas Posch1,*, Karel Simek2,3, Jaroslav Vrba2, Jakob Pernthaler4, Jirri Nedoma2, Birgit Sattler1, Bettina Sonntag1, Roland Psenner1 1Institute for Zoology...
AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsSpecials 12:49-63 (1997) - doi:10.3354/ame012049 Community structure, picoplankton grazing and zooplankton control of heterotrophic nanoflagellates in a eutrophic reservoir during summer phytoplankton maximum Simek K, Hartman P, Nedoma J, Pernthaler Springmann D, Vrba Psenner R An intensive 5 wk study was conducted investigate...
There have been some arguments concerning supplementary feed (cereals) based common carp production in fishponds and water pollution, mostly Central Europe. Using Czech Republic (top producer EU) as a benchmark combining data on nutrient digestibility of feedstuffs used combined with analyses literature data, we assessed – footprint (∼9.4–10.8 kg N ha−1, ∼2.7–3.2 P ha−1; 1.5–4 × < EU crop-livestock sectors); utilization efficiencies (NUEN ∼36%, NUEP ∼50%; 1.5–1.7 > livestock average);...
Summary ELF ® 97 phosphate (ELFP) is a phosphatase substrate which produces alcohol (ELFA), fluorescent water‐insoluble product, upon hydrolysis. We studied the kinetics of ELFA precipitation in freshwater samples at levels total plankton and single phytoplankton cells, tested suitability ELFP for measurement surface‐bound algal extracellular phosphatases. Samples from acidic Plešné Lake (pH ∼ 5; high activity) eutrophic Římov reservoir ∼7–10; moderate were incubated with 5–300 min, fixed...
Abstract: A new ELF (enzyme labelled fluorescence) assay was applied to detect phosphatase activity in glandular structures of 47 carnivorous plant species, especially Lentibulariaceae, order understand their digestive activities. We address the following questions: (1) Are phosphatases produced by plants and/or inhabitants traps? (2) Which type hairs/glands is involved production phosphatases? (3) Is this a common feature among or it restricted evolutionarily advanced species? Our results...
• Here, enzymatic activity of five hydrolases was measured fluorometrically in the fluid collected from traps four aquatic Utricularia species and water which plants were cultured. In empty traps, highest always exhibited by phosphatases (6.1–29.8 µmol l−1 h−1) β-glucosidases (1.35–2.95 h−1), while activities α-glucosidases, β-hexosaminidases aminopeptidases usually lower one or two orders magnitude. Two days after addition prey (Chydorus sp.), all noticeably decreased foliosa U. australis...
We studied the atmospheric deposition of phosphorus (P) forms along an elevation gradient, and its contribution to total external P loading lakes in Tatra Mountains Bohemian Forest, from 1998 2009. The aim was evaluate how topographical (soil vegetation pools catchment) morphological (catchment‐to‐lake area ratio) characteristics catchment–lake systems affect in‐lake nutrient structures remote mountain areas. Concentrations dissolved organic carbon (DOC), (TP), nitrogen (TON) were closely...
Abstract Metadata from 70 research articles on Cyprinus carpio digestibility published between 1973 and 2017, covering 71 feed ingredients, were analysed. Interquartile range (IR) of nitrogen (N) phosphorus (P) content in feedstuffs was 5–8% 0.7–1.2% dry matter, respectively, with digestible N:P 7.2:1–44.1:1. IR N (79–99%) high, whereas P (27–47%) rather poor. Dietary energy (gross non‐protein energy) >76%. Higher caused significant negative interferences for digestibility. nutrient carp...
Man-made shallow fishponds in the Czech Republic have been facing high eutrophication since 1950s. Anthropogenic and feeding of fish strongly affected physicochemical properties water its aquatic community composition, leading to harmful algal bloom formation. In our current study, we characterized phytoplankton across three eutrophic ponds assess dynamics during vegetation season. We microscopically identified quantified 29 cyanobacterial taxa comprising non-toxigenic toxigenic species....
Abstract We investigated the effects of strong top-down control by high fish stock on structure and seasonal dynamics plankton in nine fishponds under conventional fishery management based auxiliary feeding during two vegetation seasons. Mean concentrations total nitrogen, phosphorus, densities phytoplankton, bacteria, heterotrophic nanoflagellates, ciliates indicated hypertrophic state fishponds, as well a markedly reduced these microbial food web components crustacean zooplankton....
Many phosphorus-deficient algae and cyanobacteria produce extracellular, mostly cell-attached, phosphatases, presumably to make ambient organically bound phosphorus available. The distribution of phosphatase activity among natural phytoplankton populations its ecological significance is largely unknown. Bulk extracellular plankton (using a standard fluorometric assay) expression phosphatases at the level single cells were studied in eutrophic Římov reservoir during three consecutive seasons....