(Co)investigator from the Department: Karolina Tahovská
Funding provider: GAAV
Duration: 2009 to 2011

Project goals: 
The aims of the project are 1) to describe N transformations in organic layers of N saturated and N non saturated soils using 15N tracer approach. Second aim is 2) to evaluate the effect of Al and Mn on N microbial assimilation by manipulative experiments. 3) determination and evaluation of concentrations, availabilities and speciation of Al and Mn in upper organic soils, as well as monitoring and evaluating their temporal variability.

Project description: 
This project is focused on N transformations in N saturated mountain forest soils, using 15N isotope labelling and molecular biology methods. The goal is to describe gross microbial N processes in soil (gross N mineralization and nitrification, respiratory/assimilatory nitrate reduction, and ammonium/ amino acid assimilation) and to quantify functional genes encoding enzymes of N assimilation (Nas, Gln). The N transformations may be influenced by toxic forms of Al and Mn in N saturated soils, therefore our next goal is to determine and evaluate the concentrations, availabilities and speciation of Al and Mn, with focus on toxicity and impact on N mineralization and N assimilation processes. The soil samples will be collected at Certovo and Plešné Lake watersheds in the National Park Šumava. The results will improve the knowledge on N transformations and fluxes in N saturated soils, as well as the knowledge about Al and Mn speciation in organic soil layers.

Principal investigator: Jan Mráz (FROV JU)
Coinvestigator from the Department: Jaroslav Vrba
Funding provider: Czech Science Foundation
Grant no.: GAČR 22-18597S
Duration: 2022 - 2024

Link to project presentation on Czech Science Foundation webpages.

Project goals:
To understand: 1) nutritional intricacies and bioenergetics of carp in fishponds; 2) nutrient retention-excretion of fish and nutrient sequestration-emission in fishponds under dynamically changing balance of nutrition and RUE (natural + supplemental feed available to fish) through vegetation season.

Project description:
Czech fishponds currently represent rather hypertrophic, turbid ecosystems resembling a high-density fish (carp) scenario. Fish may act as a source of readily available nutrient to the environment or excavate nutrients from the ecosystem. Carp nutrition research is among the strongest pillars in fish nutrition knowledgebase. It has seldom been used as a lens to look at water pollution problems. Seasonally shifting diet scenarios may have implications on carp nutritional bioenergetics. Through digestibility-metabolic losses-retention experiments using semi-purified research diets and/or mimicked fishpond diets or direct field experiments, we intend to unravel how carps aggravate or suppress retentions (and excretions) based on different molecular (organic molecules containing N, P) stoichiometry despite same N:P, bioavailable P homeostasis, non-protein energy:protein balance, bioavailable P:protein (N) quality balances, synergistic contribution of natural food, adverse environmental conditions with changing gut food stoichiometry, anti-nutritional factors of terrestrial feedstuffs.

Principal investigator: Jan Mráz (FROV JU)
Coinvetsigator from the department: Jaroslav Vrba
Funding provider: The Ministry of Agriculture of the Czech Republic
Grant no.: NAZV QK22010177
Duration: 2022 - 2025

Project goals:
The aim of the project is to optimize the feeding and management of pond aquaculture for efficient resource management and a more positive impact on the environment.

The partial goals are:

1. Increased feeding efficiency, better use of natural production potential, better growth at lower feed costs, lower negative impact on the environment.
2. Reduction of waste nutrient production.
3. Optimization of pond management tools in terms of environmental impact and economics.
4. Diversification of cultured fish in polycultures and better valorisation of fish.
5. Quantification of environmental benefits of pond aquaculture in different farming systems.
6. Evaluation of economic benefits of various pond farming systems, evaluation of trends in the economics of pond aquaculture.

Principal investigator: RNDr. Lubomír Adamec, CSc.
(Co)investigator from the Department: Jaroslav Vrba
Duration: 2011 - 2014

Project description: 
Rootless Utricularia is the largest carnivorous plant genus, with some of the smallest angiosperm genomes found. We argue that the mutualistic plant-microbe interaction in the bladder traps of aquatic Utricularia has a profound effect on plant ecophysiology, mainly nutrient (N, P) acquisition, and leads to changing plant growth and gene expression patterns. We will test this by identifying key metabolic, microbe-dependent pathways allowing us to conclude the role of microbes in nutrient gain of Utricularia. We plan to use recent high-throughput sequencing advances, which now allow us to compare entire transcriptomes from both axenically growing U. vulgaris and plants in various stages of microbial colonization. The analysis of genome-wide differential RNA expression will provide us with greater insights into biological pathways and molecular mechanisms that underlie the plant-microbe association. Sequence data will be supported by the data from growth experiments, stable isotope and nutrient analyses, and studies on microbial community development and its physiological status.

Related links:
http://utricularia.prf.jcu.cz