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Dr. Khrys Duddleston

Khrys Duddleston, Ph.D.

Professor & Director of Biological Sciences
Department of Biological Sciences
(907) 786-7752


  • 1998 Ph.D. Microbiology, Oregon State University
  • 1993 M.S. Biology, Va. Tech
  • 1990 B.S. Biology (Option: Microbiology), Virginia Polytechnic Institute and State University (Va. Tech)

Teaching Responsibilities

  • BIOL A242: Fundamentals of Cell Biology
  • MBIO A340: Microbial Biology
  • BIOL A365: Astrobiology (Team taught with Travis Rector, Astronomy and Physics)
  • MBIO A450/650: Microbial Ecology
  • MBIO A410: Microbial Physiology

Research Interests

Research in the Duddleston lab currently focuses on three areas of inquiry: gut microbial ecology, soil microbial ecology and diversity, and aquatic environmental microbiology. Specifically, the Duddleston lab is examining the gut microbial community of arctic ground squirrels. The radical shifts in physiology experienced by arctic ground squirrels make then an excellent model with which to study a) the response of microbial populations to changes in their environment and b) the complex reciprocal interactions between the host and the gut microbiota as they relate to health and disease. We are particularly interested in the potential beneficial role of gut microbes in protein conservation during hibernation and in the increase in adiposity that occurs in advance of hibernation. The Duddleston lab also focuses on the impact of contaminants such as herbicides, oil and oil-spill response chemicals on the diversity of microbial communities in soil and water. Lastly, the Duddleston lab also examines sources and transport mechanisms of microbial contaminants in freshwater systems in urban and rural settings, with the ultimate goal of understanding the link between source, transport, and human disease.


  • Hatton, Jasmine J., Timothy J. Stevenson, C. Loren Buck and Khrystyne N. Duddleston. 2017. Diet affects arctic ground squirrel gut microbial metatranscriptome independent of community structure. Environ. Microbiol. 19(4):1518-1535.  PMID: 28251799; PMCID: PMC5417852.
  • Mutter, Edda A., William E. Schnabel and Khrystyne N. Duddleston. 2016. Partitioning and transport behavior of pathogen indicator organisms at four cold region solid waste sites. J. Cold Reg. Eng. 10.1061/(ASCE)CR.1943-5495.0000111
  • Tomco, Patrick L., Khrystyne N. Duddleston, Emily Jo Schultz, Birgit Hagedorn, Timothy J. Stevenson and Steven S. Seefeldt. 2016. Field degradation of aminopyralid and clopyralid and microbial community response to application in Alaskan soils. Environ. Toxicol. Chem. 35(2):485-493. DOI: 10.1002/etc.3222
  • Lupfer, Gwen, Eric S. Murphy, Zoe Merculieff, Kori Radcliffe and Khrystyne N. Duddleston. 2015. Adapting to alcohol: Dwarf hamster (Phodopus campbelli) ethanol consumption, sensitivity, and hoard fermentation. Behav. Proc. 115:19-24
  • Stevenson, T.J., Duddleston, K.N. & Buck, C.L. (2014). Effects of season and host physiological state on the diversity, activity and density of the arctic ground squirrel cecal microbiota. Applied and Environmental Microbiology, 80(18), pp. 5611-5622. doi: 10.1128/AEM.01537-14.
Note: This paper was chosen by the editors of AEM for inclusion in "Spotlight," a journal feature highlighting research articles in an issue that have been deemed of significant interest.
  • Carey, H.V. & Duddleston, K.N. (2014). Animal-microbial symbioses in changing environments. Journal of Thermal Biology, 44, pp. 78-84. doi: 10.1016/j.jtherbio.2014.02.015
  • Stevenson, T.J., Buck, C.L. & Duddleston, K.N. (2014). Temporal dynamics of the cecal gut microbiota of juvenile arctic ground squirrels: a strong litter effect across the first active season. Applied and Environmental Microbiology, 80(14), pp. 4260-4268. doi: 10.1128/AEM.00737-14
  • Schnabel,W. E., T.L. Wilson, R. Edwards, G. Stahnke, M. Maselko, D. C. Maddux, and K. N. Duddleston. 2010.Variability, Seasonality, and Persistence of Fecal Coliform Bacteria in a Cold-Region Urban Stream. Journal of Cold Regions Engineering. 24(2):54-75
  • Hines, M. E., K. N. Duddleston, J. N. Rooney-Varga, D. Fields and J. P. Chanton. 2008. Uncoupling of acetate degradation from methane formation in Alaskan wetlands: Connections to vegetation distribution. Global Biogeochem. Cycles. 22, GB2017, doi:10.1029/2006GB002903.
  • Rooney-Varga, J. N., M. W. Giewat, K. N. Duddleston, J. P. Chanton and M. E. Hines. 2007. Links between Archaea community structure, vegetation type, and methanogenic pathways in Alaskan peatlands. FEMS Microbiology Ecology. 60(2):240-251.
  • Duddleston, K. N., M.A. Kinney, R.P. Kiene and M.E. Hines. 2002. Anaerobic microbial biogeochemistry in a northern bog: acetate as a dominant metabolic end product. Global Biogeochem. Cycles.16(4):1063, doi:10.1029/2001GB001402,2002.
  • Duddleston, K. N., D.J. Arp and P. J. Bottomley. 2002. Biodegradation of monohalogenated alkanes by soil NH3- oxidizing bacteria. Appl. Microbiol. Biotechnol. 59:535-539.
  • Hines, M.E., K. N. Duddleston, and R.P. Kiene. 2001. Carbon flow to acetate and C1 compounds in northern wetlands. Geophys. Res. Lett. 28:4251-4254. 
  • Duddleston, K. N., P. J. Bottomley, A. J. Porter, and D. J. Arp. 2000. Effects of soil and water content on methyl bromide oxidation by the ammonia-oxidizing bacterium, Nitrosomonas europaea.Appl. Environ. Microbiol. 66:2636-2640.
  • Duddleston, K. N., P. J. Bottomley, A. J. Porter, and D. J. Arp. 2000. New insights into methyl bromide cooxidation by Nitrosomonas europaea obtained from experimenting with moderately low density cell suspensions. Appl. Environ. Microbiol. 66:2726-2731.

Selected Abstracts and Presentations

  • *Carlson, K. M., C. L. Buck and K. N. Duddleston. 2017. Ureolytic microbes and urea-nitrogen salvage in the arctic ground squirrel gut. ASM Microbe. June 1-5, 2017, New Orleans, LA
  • Gering, S. M. and K. N. Duddleston. 2017. Ureolytic gut microbes and UT-B transporters in arctic ground squirrels. ASM Microbe. June 1-5, 2017, New Orleans, LA
  • *Rouse, N., K. Duddleston, K. Counihan and D. Boege-Tobin. 2017. Environmental persistence of Streptococcus infantarius ss coli and Streptococcus phocae: Bacteria responsible for significant mortality of northern sea otters in Resurrection and Kachemak Bays, Alaska. ASM Microbe. June 1-5, 2017, New Orleans, LA
  • Vandersommen, V. M., S. Gerken, K. N. Duddleston and B. R. Briggs. 2017. Discovering the presence or absence of gut microbies in Crustacea: Cumacea. ASM Microbe. June 1-5, 2017, New Orleans, LA
  • Duddleston, K. N. 2017. Investigating the gut microbial community of an extreme hibernator, the arctic ground squirrel. Annual Meeting of the Society for Integrative and Comparative Biology. Jan. 4-8, 2017, New Orleans, LA.
  • Duddleston, K. N., J. J. Hatton* and C. L. Buck. 2016. Dietary fat and calorie content influence gene expression but not community composition of gut microbiota in arctic ground squirrels. 6th ASM Conference on Beneficial Microbes. Sep 9-12, 2016. Seattle, WA.
  • Duddleston, K. N., J. J. Hatton* and C. L. Buck. 2016. Dietary fat and calorie content influence activity but not diversity of gut microbes in arctic ground squirrels. 16th International Symposium on Microbial Ecology. Aug 21-26, 2016. Montreal, Canada.
  • Buck, C. L., J. J. Hatton* and K. N. Duddleston. 2016. Effect of diet on the arctic ground squirrel gut microbiota and pre-hibernation fattening. 15th International Hibernation Symposium. Jul 31-Aug 4, 2016. Las Vegas, NV
  • *Hatton, J. J., S. F. Cain, C. L. Buck and K. N. Duddleston. 2015. The gut microbiota and pre-hibernation fattening in arctic ground squirrels. 115th General Meeting of the American Society for Microbiology, May 29-June 1, 2015, New Orleans, LA
  • Cayabyab, C., *J. Hatton and K. Duddleston. 2015. Development of a qPCR assay to enumerate bacteria in arctic ground squirrel ceca. 115th General Meeting of the American Society for Microbiology, May 29-June 1, 2015, New Orleans, LA
  • Wilson, C. D., T. J. Stevenson, J. A. Stecyk and K. N. Duddleston. 2015. Influence of cold temperature   and anoxia on the Red-eared Slider Turtle gut microbiota. Annual Meeting of the Society for Integrative and Comparative Biology, Jan. 3-7. 2015, West Palm Beach, FL 
  • Duddleston, K.N., and P.F. Sullivan. 2014. Composition of soil microbial communities at the Arctic treeline in Northwest Alaska. Abstracts of the 114th meeting of the American Society for Microbiology. May 16-20, 2014. Boston, MA. 
  • Schultz, Emily and Khrystyne Duddleston. 2014. The effects of Aminopyralid treatment on microbial diversity in Alaskan soils. The 10th Annual Undergraduate Research & Discovery Symposium, UAA, Anchorage, AK, April 2014.
  • Michele, M.D., J.E. Mellish, and K.N. Duddleston. 2013. Characterizations and changes in gut flora with acute stress in endangered Stellar Sea Lions. The 9th Annual Undergraduate Research & Discovery Symposium, UAA, Anchorage, AK, April 2013.
  • Duddleston, K., *T. Stevenson and C. Loren Buck. 2012. Dynamics of the gut-microbial communities in arctic ground squirrels: effects of development and hibernation. Abstracts of the 14th International Symposium on Microbial Ecology. Aug. 18-24, 2012. Copenhagen, Denmark.
  • Sinnott, D., B. Quinlan, *T. Stevenson, K. Duddleston. 2012. Effects of diet change and antibiotics on the gut microflora diversity of arctic ground squirrels. 6th Annual Symposium of the REU: Ecology and Physiological Ecology in Alaska. Aug. 3, 2012. Anchorage, AK.

Career History/Work Experience

  • ENRI Faculty Fellow
  • Alaska INBRE Faculty Affiliate 
  • Biology Scholar-in-Residence. Biology Scholars Transitions Residency: From Science Education Research to Publication.
  • American Society for Microbiology Scholar-in-Residence. Institute on the Scholarship of Teaching and Learning.
  • UAA Faculty Writing Fellow. UAA Writing Across the Curriculum Initiative.