Sökning: "microbial loop"
Visar resultat 1 - 5 av 9 avhandlingar innehållade orden microbial loop.
1. Utilization of terrestrially derived dissolved organic nitrogen by aquatic bacteria
Sammanfattning : I investigated the bacterial utilization of terrestrially derived dissolved organic nitrogen (DON) in aquatic ecosystems, and assessed the potential role of river-born DON in marine eutrophication. To determine the bioavailability of DON, I developed a bioassay employing N-limited bacterial regrowth cultures, which were calibrated with additions of inorganic nitrogen. LÄS MER
2. Viral Loop Dynamics in Temperate and Polar Freshwaters
Sammanfattning : All cellular organisms in aquatic environments are susceptible to virus attack. Viruses are the smallest but most abundant biological entities in freshwaters. This thesis describes interactions between viruses and bacteria in temperate and polar freshwaters with particular emphasis on Arctic and Antarctic aquatic systems. LÄS MER
3. Functional and structural characterizations of phytoplankton-bacteria interactions in response to environmental challenges
Sammanfattning : Microorganisms, such as phytoplankton and bacteria, make up ≈70% of aquatic biomass and contribute 50-85% of the oxygen in Earth’s atmosphere. The microbial loop concept and the discovery of the large diversity in microbial communities acknowledge that biotic interactions between microorganisms in addition to resource competition enable the recycling of energy and nutrients in aquatic food webs. LÄS MER
4. The role of terrestrial and phytoplankton-derived organic matter in planktonic food webs
Sammanfattning : Lakes are important global ecosystems and many of them are nutrient-poor (unproductive). Especially in northern boreal latitudes, lakes may be heavily subsidized by terrestrial organic material (t-OM) from peat layers in the catchment. LÄS MER
5. Defense-peptides against mycobacteria
Sammanfattning : Several members of the genus Mycobacterium can cause serious infections in both man and animal. One of the world's most serious infectious diseases, tuberculosis, is caused by the pathogen Mycobacterium tuberculosis. Specific defense to tuberculosis/mycobacteriosis is dependent on the individual's ability to mount a proficient immune response. LÄS MER