ESR7 Vaidotas Kisielius – University of Copenhagen

NaToxAq > PhD Projects > ESR7 Vaidotas Kisielius

ESR7 Vaidotas Kisielius

Project: Spatial and temporal variation in the production and release of glycosidal natural toxins in rangelands and forests

Principal supervisor: Dr. Lars Holm Rasmussen

Intro to project:

The chemicals of this project are primarily limited to glycosidic natural toxic compounds originating in non-managed ecosystems. This is a very diverse group of substances which often act in plants as insect repellents and grazing deterrents. The molecular structure of the glycosides makes them highly water soluble and mobile in the soil. Mammalian intestines as well as natural environments such as soils and waters contain multiple enzymes of microbial origin that efficiently hydrolyse glycosidic bonds. On several occasions this group of toxins has been identified in soil and water environments. Their general adverse effects such as acute toxicity to aquatic organisms are also commonly recognised. The natural abundance, mobility and toxicity of the glycosidic toxins make them excellent candidates for tracing and collecting, gathering relevant data, performing thorough analysis and putting forward the relevant arguments to support or oppose the hypothesis that naturally appearing biological toxins inhibit the quality of the drinking water supplies.

In order for this PhD project to provide qualitative rather than quantitative results, it will restrict itself to few chemicals (the “Starting List”) and progress by adding few additional compounds in its later stage (the “Expanded List”).

The chemical compounds of the Starting List have been selected based the on several principal constrains regarding their molecular structures, potential intensity and type of toxicity and potential ability to enter water bodies and endure in them. Regarding the toxicity type, the Starting List has been chosen to comprise chemicals that are carcinogenic. To ensure possible leaching to water, the chemicals will also be restricted to the compounds which have been detected in water bodies by previous studies. The physical molecular parameters such as vapour pressure, partition coefficient and water solubility, indicating mobility in the soil-water environments will be reported and the duration in waters and soils will be measured experimentally. The method for separation and identification of the chemical compounds will be developed and the dynamics of concentrations of these substances in waters and soils will be measured and mapped.

The list of the studied toxins will be expanded before the vegetation season of 2018 based on the similar criteria through the course of exchanging information in the Natoxaq network.