Our techniques include e.g. molecular biology techniques (16S rRNA sequencing, next-generation sequencing, protein isolation and purification, electrophoresis), modern metabolomics, spectroscopic and chromatographic methods (FT-IR, EDX, GC-MS, HPLC), tracer techniques and imaging techniques (TEM, SEM, autoradiography).
Soil microorganisms show impressive diversity and one of their most important features is their biochemical versatility.There are several processes found in soil microbiota, which affect the geochemical cycle of elements, including native biosorption, oxidation, reduction, enzymatic transformations, accumulation and precipitation. Oxidation-reduction processes are highly significant in the environment and are affected by microorganisms. Microorganisms can use several substances as an electron donor or as an electron acceptor. The most prevailing electron donor is by far organic carbon. When oxygen is not present, microorganisms can use alternative electron acceptors like nitrate, selenite, manganese, iron, arsenic or sulphur. Various micro-organisms have also developed different metal resistance processes which include changes in the oxidation state of toxic metals.
In our group various retardation processes (uptake, protein structures involved in uptake, retardation, reduction, oxidation) of radionuclides, heavy metals and nutrients (i.e. Se, U, Ra, Ni, Cr, Fe) in environmental bacteria as well as their metal-metabolism are studied.
The deep subsurface environment harbours a striking number of different bacterial and archaeal species and the continental deep biosphere has been estimated to represent up to 19% of the Earth’s biomass. However, despite intensive research on deep terrestrial subsurface (DTS) microbial communities and metabolism in recent decades, the deep continental bedrock still remains one of the least understood habitats on Earth.
Information on microbial metabolism in the deep subsurface environment is especially important for industries that rely on the stability of the DTS, including hydrocarbon industry, CO2 capture and storage (CCS), and the deep geological disposal of hazardous waste. Microbial processes may play a significant role in the long-term stability of such a storage and understanding the role of the microbial communities and their metabolism in these deep terrestial environments is therefore of critical importance for the safety of any such industry.
Microbiota have essential roles in soil biogeochemical cycles and readily respond to the changes occurring in the soil conditions due to toxic compounds, including radionuclides. The level of radiological exposure of humans and other biota to radionuclides from different sources (e.g. uranium mines, disposal of spent nuclear fuel) depends on the environmental dispersion, migration and retention as well as transfer pathways of these radionuclides. Many of these transfer pathways include microbiological steps and mediators, which are however still largely unknown. Therefore, the characterization of microorganisms in such radionuclide-polluted environments is important and improves our understanding of the impacts of radionuclides on microbial ecology and evolution and vice versa. This also helps in the understanding of the mechanisms of microbial radionuclide tolerance. To address these questions, we use amplicon sequencing approaches combined with isolated bacterial strains and batch uptake and leaching
experiments of radionuclides from different type of environmental samples, including former pilot-scale uranium mine and oligotrofic mire envionments.
Our research aims to improve future phytoremediation and agricultural practices globally by providing detailed research data on soil microbial and plant interaction processes, especially in the healthy growth of plants as well in the accumulation of agriculturally important trace elements in crops. Heavy-metals, radionuclides and trace elements enter the food chain through plants which take it up from the soil. Plants are in continuous contact with soil microbiota, which can modify soil chemical environment and affect the availability of chemical elements for plant-uptake. Especially because of these interactions, the role of plant-bacterial synergy in reducing regional heavy-metal and radionuclide load or toxic trace element levels is essential and knowledge of the bacterial processes associated with the metabolism of these elements is of importance. The aim of our study is to identify the major metabolic pathways involved in heavy-metal/radionuclide accumulation in plants and the importance of bacterial-plant interactions in the shapeability of these pathways.