Research Category

Through field studies at a common tree garden at Kevo Subarctic Research Station near Utsjoki, Finland (managed by the University of Turku), we’re investigating the role of plant secondary compounds in controlling soil microbial processes such as litter decomposition and contaminant biodegradation. Multi-year studies are in progress to understand the soil microbial ecology and litter decomposition of plants with different levels of secondary compounds due to different evolutionary histories of herbivore pressure (e.g. birch from Iceland, Finland, Siberia, and Alaska). We hypothesize that high concentrations of secondary compounds inhibit litter decomposition and build soil C stocks, while also selecting for microbes that target aromatic compounds, which could enhance contaminant biodegradation potential. We’re using next-generation DNA sequencing and stable isotope probing methods to characterize differences in microbial communities, genes, and functions.

The Broader Impacts components of this project includes a major arts-humanities-science exhibit, In a Time of Change: Microbial Worlds.  The exhibit features works created by artist-in-residence Stephanie Rae Dixon (Brooklyn, NY) who joined our research team in Finland, as well as 12 Alaska-based artists and writers working on a variety of other microbiological themes.

Financial support was provided by a grant from the National Science Foundation   DEB-1257424. Additional support was provided by Institutional Development Awards (IDeA) from the National Institute of General Medical Sciences of the National Institutes of Health under grant number P20GM103395, from the National Center for Research Resources (NCRR) under grant number 5P20RR016466, from the Ministry of Education, Youth and Sports of the Czech Republic no. LH 14004, and from the Czech Science Foundation under grant number 13-28283S.

The second largest contaminated site in Alaska resides beneath the city of North Pole, where hundreds of private drinking water wells have been contaminated with the industrial solvent sulfolane. In collaboration with David Barnes (UAF Institute of Northern Engineering) and Jan Sunner (University of Oklahoma), we’re working to assess biodegradation rates, groundwater flow patterns in discontinuous permafrost, to identify organisms and processes responsible for biodegradation, and to investigate the safety and efficacy of various cleanup systems including household drinking water filtration units.

Funded has been provided by the Alaska Department of Environmental Conservation, Alaska INBRE and USGS NIWR, as well as several URSA grants to support undergraduate research and through fellowship to Ph.D. student Chris Kasanke from Alaska INBRE.

Undergraduate researcher Michael Willis collecting groundwater samples

The Leigh Lab investigates the role of microorganisms in the biodegradation of environmental contaminants and in biogeochemical cycling. Our research topics include biodegradation of oil and dispersants in Arctic seawater, biodegradation of groundwater contaminants (e.g. sulfolane), the use of plants and microbes to remediate contaminated soils (phytoremediation), methane oxidation in Arctic lakes, and boreal forest ecology. We also organize efforts to foster collaboration between the environmental sciences, arts, and humanities, produces art-science exhibits and performances for the public, and conduct collaborative research on the impacts of these activities on audiences.