Projects / Programmes
Mikrobna fiziologija in mikrobna ekologija (Slovene)
January 1, 1999
- December 31, 2003
Code |
Science |
Field |
Subfield |
4.03.00 |
Biotechnical sciences |
Plant production |
|
1.05.00 |
Natural sciences and mathematics |
Biochemistry and molecular biology |
|
1.03.00 |
Natural sciences and mathematics |
Biology |
|
Code |
Science |
Field |
B230 |
Biomedical sciences |
Microbiology, bacteriology, virology, mycology |
P004 |
Natural sciences and mathematics |
Biochemistry, Metabolism |
B410 |
Biomedical sciences |
Soil science, agricultural hydrology |
B433 |
Biomedical sciences |
Fixation of nitrogen |
B260 |
Biomedical sciences |
Hydrobiology, marine biology, aquatic ecology, limnology |
Researchers (12)
Organisations (1)
Abstract
Research activities of our group are focused on the regulation of the microbial processes involved in nitrogen metabolism on the physiological and ecological level. Mineralization/immobilization, nitrification, denitrification and molecular nitrogen fixation are studied in laboratory model systems and the results verified in complex natural environments such as soil and water.
1. Mineralization/immobilization: Environmental factors (pH, temperature, substrate, oxygen and water availability), controlling the conversion of mineral nitrogen into microbial biomas and its persistence in soil are of prime interest.
2. Nitrification: Preliminary results indicate that pH and oxygen availability affect the accumulation of nitrite during nitrification. Regulatory role of these two factors in nitritation and nitratation will be studied in detail. Accumulation of nitrite during nitrification is of biotechnological (practical) significance for the removal of excess nitrogen in waste waters by simultaneous nitrification and denitrification
3. Denitrification: Dissimilatory nitrate reduction is enabled by membrane bound nitrate reductase (NR). In addition to NR, some bacterial strains posses periplasmic nitrate reductase (NAP) the physiological role of which is as yet not entirely understood. Our research group has isolated NAP from Pseudomonas stutzeri. Physiological role of the enzyme will be studied in the future, using nap mutants.
4. Biological nitrogen fixation: Studies are concerned with: a) criteria for the selection of superior symbiotic partners in R.leguminosarum/Phaseoulus and R. meliloti/Trigonella symbioses, b) liquid inoculant formulations of Rhizobium/Bradyrhizobium spp., and c) the role of fixed nitrogen in nitrogen balance of soil and nonsymbiotic plants.
5. Microbial communities: The structure of microbial community participating in nitrogen transformations in soil and water is being studied in relation to environmental factors, using molecular biology techniques. The effect of viruses on bacterial population and thereby on the flow of nitrogen, carbon and other nutrients are being examined. The effect of host energy status on prophage induction is studied on the molecular level. The role of horizontal and vertical gene transfer in the structure and dynamics of microbial communities will be investigated. The research is focused on pheromone signaling and regulation of development of genetic competence in selected bacterial strains isolated from the environment.
Significance for science
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Most important scientific results
Final report
Most important socioeconomically and culturally relevant results
Final report