People
Alexander Tøsdal Tveit – Associate Professor
Research interests
I am a microbiologist with a PhD in microbial ecology from UiT, The Arctic University of Norway. I work with microorganisms that are involved in the production and consumption of methane and carbon dioxide, and how they interact in soils and sediments. In particular i want to understand how climate change influences microbial physiology and the effects on carbon cycling.
Currently I am leading the research lab and team Cells in the Cold (CECO) laboratory with financial support from Tromsø research foundation and the research council of Norway. In our lab we perform studies in three major directions where the aim of each part is to contribute knowledge about microorganisms with an important role in global carbon cycling.
I) Physiology and ecology of atmospheric methane oxidizing bacteria and other methanotrophs.
We have isolated the first pure culture of an atmospheric methane oxidizing bacterium and characterized it phylogenetically, genomically and functionally. These initial findings were published in PNAS in 2019 and the study was awarded the prestigous Cozzarelli Prize by the National academy of sciences, USA (See CV in attachments). Now we are working to identify the phylogenetic distribution of atmospheric methane oxidation and to understand how they are able to live on trace-gases in air. Ongoing experiments will also uncover how these microorganisms react to the atmospheric composition predicted for the future and how they survived under the lower greenhouse gas concentrations in the atmosphere prior to the industrial revolution. From recent findings we also see a large untapped biotechnological potential in these organisms and are preparing for moving in an applied direction in the coming years.
II) Long-term soil warming effects on microbial metabolisms
Using geothermally warmed grassland soils in Iceland as a model system we study how the metabolic activities of specific microbial populations are modulated in soils affected by long term warming. Our recent study, published in Science in April 2022 (See CV in attachments), demonstrate that adjustments of the protein biosynthesis machinery is central to how soil microorganisms respond to global warming. This study has attracted alot of attention from our colleagues and may represent critical knowledge for understanding global warming effects on soil ecosystems.
III) Carbon cycling in Arctic peatlands.
We are studying how organic matter in Arctic peatlands is degraded, which organisms are involved and how they interact. This includes general physiological responses to temperature, organisms involved in syntrophy and methanogenesis, and also microbial food web interactions. Our work on this springs from three studies published in PNAS and ISME in 2013 and 2015 (See CV in attachments).
Currently, three topics within this direction are of primary interest to us:
1) Microbial physiological responses to temperature change, focusing on protein biosynthesis adjustments.
2) Effects of above-ground herbivory and plant community changes on the microbial foodweb dynamics and methanotrophic community below-ground
3) Anaerobic carbon dioxide fixation, which may be an important but overlooked process in Arctic peat.
Mette Marianne Svenning – emeriti
My research focus is study of the biodiversity and activity of microbial communities in northern high organic ecosystems, with different molecular methods and classical microbiology. Studies are done in the field, in controlled laboratory experiments and on pure cultures. Novel methods for isolation, cultivation and experimental studies of methane oxidizing bacteria are applied to address their importance as biological filter for methane in terrestrial and marine ecosystems. Our laboratory holds a unique culture collection of methane oxidizing bacteria.
I am the team leader for the Cold-loving Microbes in a Warming Arctic research group in CAGE Centre for Arctic Gas Hydrate, Environment and Climate (https://cage.uit.no/)
Anne Grethe Hestnes – Senior Engineer
Andrea Söllinger – Researcher
I am a microbiologist and microbial ecologist by training and still fascinated by the tremendous impact microorganisms have on our planet and all life on Earth.
In my early scientific life (besides microscoping dead grasshoppers at the age of ten), I studied and cultivated, at that time poorly characterized, methane producing microorganisms (methanogens), the Methanomassiliicoccales, focusing on their role in the global carbon cycle and their importance as greenhouse gas producers.
During my PhD at the University of Vienna, Austria, and the University of Greifswald, Germany (where I stayed for a postdoc position), I started to use metatranscriptomics, metagenomics, and proteomics to study microorganisms in pure culture as well as complex free-living and host-associated microbial communities with relevance for greenhouse gas mitigation, human health, and ecosystem stability.
In early 2019, I moved into the Arctic and adapted my personal and my scientific work to colder temperatures. Within the project Cells in the Cold, led by Alexander T. Tveit, and the international ForHot project, I am currently focusing on investigating functional changes in cold-adapted microbial communities in soils exposed to warming.
Recently, we identified the first common microbial physiological response to weeks, years, and decades of grassland soil warming (+6 °C) – the downregulation of the bacterial protein biosynthesis machinery (Söllinger et al., Science Advances, 2022). In other words, cellular numbers of ribosomes, the macromolecular complexes synthesising proteins, are reduced at higher temperatures. By reducing the cellular ribosome content, substantial amounts of energy and matter can be spared and potentially re-allocated.
In my ongoing and future work, I want to follow up on these findings and reveal the relevance of cellular ribosome reduction across seasons and ecosystems, expanding from soil to freshwater and marine systems. Furthermore, I want to assess multifaceted consequences including alterations of terrestrial and aquatic food webs and greenhouse gas emissions, ultimately needed to project and manage climate change impacts on Arctic ecosystems and human welfare in the High North.
Follow one of the links below to access my publications:
Tilman Schmider – Head Engineer
Atmospheric methane oxidizing bacteria are the only known biological sink for atmospheric methane, a potent greenhouse gas responsible for about 20% of global warming. Despite the discovery of atmospheric methane oxidation by bacteria in the early 90s, the first known atmospheric methane oxidizer in pure culture was described in 2019. Based on the unique availability of these microorganisms in pure culture at the UiT, it is finally possible to assess their physiology and investigate the traits that enable life on air. During my PhD, I focus on the physiological basis of these bacteria to live on trace amounts of methane and the related energy harvest during methane oxidation.
Oliver Schmidt – Postdoctoral Fellow
Oliver is currently working in the LoAir project focusing on the intriguing metabolism of atmospheric methane-oxidizing bacteria (atMOB). Atmospheric concentrations of the potent greenhouse gas methane increased since the industrial revolution in the 18th century from 0.7 ppm to 1.9 ppm today. However, methane is still emitted in large quantities by natural and anthropogenic processes and its atmospheric concentrations are predicted to increase further (to 2.5 ppm towards the end of the 21st century) if the efforts to limit methane emissions are not intensified. atMOBs are an important sink for atmospheric methane globally and to study the metabolic responses of these microbes to changes in atmospheric methane concentrations is of utmost importance for predicting future climate change. Oliver designed an experimental setup to cultivate Methylocapsa gorgona MG08, a model atMOB, at different methane concentrations resembling past, present and future predicted atmospheric levels of the greenhouse gas. In order to characterize the metabolic adaption of M. gorogna to contrasting substrate availabilities he combines analytical (gas chromatography), molecular (nucleic acid and protein quantitation, proteomics), and microscopic techniques.
Yngvild Bjørdal – Doctoral Research Fellow
Julia Brzykcy – Doctoral Research Fellow
Ragnhild Helene Grøholt Prytz – Master student
Bente Lindgård – Senior Engineer
