Erica B. Young
Erica B. Young
Associate Professor
Algal and Microbial Biogeochemical Processes

BSc University of Western Australia 1988
PhD Monash University 1999
Postdoctoral Research Fellow
Queen's University of Belfast 1999-2002

Office: Lapham S593
Phone: 414-229-3257
FAX: 414-229-3926
Laboratory Homepage

Research Interests

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Algal and Bacterial Community Ecophysiology


My research on algae is focused on photosynthesis, nutrient acquisition and nutrient transformations and assimilation. A key area of research in my lab isphosphorus acquisition by freshwater phytoplankton and benthic filamentous algae. Our research includes examining expression and function of alkaline phosphatase, use of a range of organic P sources, and the ecological role of viral lysis of bacteria and phytoplankton in release of scarce phosphorus in freshwater ecosystems. In the lab, we use enzyme assays, genetic analysis, microscopic localization techniques, flow cytometry, measures of photosynthesis and elemental analysis to examine P acquisition in algal cultures and natural phytoplankton assemblages from Lake Michigan and other freshwater ecosystems. We are also examining N transformation processes, particularly nitrate reductase and other N assimilation enzymes in marine macroalgae and freshwater diatoms. We are using enzyme activity assays, protein determinations and genetic techniques to examine nitrate reductase genes.

Another core area is the interactions between algae and their bacterial partners in communities. Interactions between algal and bacterial community partners facilitate transformation of nutrient elements and compounds within natural and anthropogenically-influenced ecosystems. We are currently examining algal-bacterial communities growing in wastewater and how they transform key nutrients. With support from US DOE-JGI, we are preparing detailed analysis of prokaryotic and eukaryotic partners in these communities, and the roles in biogeochemical cycling by exmaining the functional genes being expressed under high nutrient conditions and high light and temperature stress.

Another forum for examining biogeochemical nutrient processes is in Pitcher Plant Microbial Communities, using carnivorous Sarracenia purpurea in the Cedarburg Bog at the UWM Field Station. Previously we examined how the plants are influenced by the availability of nutrients in the surrounding wetland environment. Now we are examining the diversity of the microbial community and the roles of bacteria in nutrient cycling within these unique inquiline communities. We are focusing on transformation of nitrogen and phosphorus via measurements of hydrolytic enzymes and presence of distinct genes involved in nutrient transformations within the pitcher fluid.

Other areas of research on algal physiology include using chlorophyll a fluorescence to assess nutrient limitation and toxins in aquatic systems. Chl a fluorescence provides rapid assessment of stress in algal cells, especially about photosynthetic processes which we have found are rapidly affected by a range of common aquatic toxins. My research interests also include inorganic carbon acquisition by algae and regulation by light, carbon dioxide and nutrient availability.Research also has focused on changes in vegetation of the Cedarburg Bog wetland using long-term vegetation survey data to investigate the spread of the invasive species Rhamnus frangula (Glossy Buckthorn) and examine the roles of recruitment and community composition in the establishment of this invasive species in different wetland communities.  


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Selected Publications

Robertson DL, Johnson C, Young EB.Examination of seasonal expression of nitrogen assimilation genes in intertidal Fucus vesiculosus. In prep.

Berg JA, Meyer GA, Reinartz JA,Young EB. Susceptibility of five wetland community types to invasion by glossy buckthorn (Frangula alnus Mill.) In prep.

Hanson AM, Berges JA, Young EB. Virus diversity and relationship to bacteria and chlorophyll across a freshwater trophic gradient in Lake Michigan watershed. In prep.

Young EB, Berges JA. 2015. Nitrogen Stress in the Marine Environment: from Scarcity to Surfeit. In. Stressors in the Marine Environment: physiological and ecological responses, societal implications.Solan M, Whiteley N. (Eds) Oxford University Press.

Engevold PM, Young EB, Sandgren CD, Berges JA. 2015. Pressure from top and bottom: lower food web responses to nutrient cycling changes and invasive species in western Lake Michigan. Journal of Great Lakes Research

Lee, PO, Mclellan SL, Graham LK, Young EB. 2014. Effects of Dreissenid mussel invasion on benthic bacterial communities in nearshore Lake Michigan. FEMS Microbiology Ecology. DOI10.1093/femsec/fiu001

Béchette A, Stojsavljevic T, Tessmer M, Berges J, Pinter G, Young EB. 2013. Mathematical Modeling of Bacteria and Virus Interactions in Lake Michigan with an Internal Phosphorus Quota. Journal of Great Lakes Research 39: 646–654.

Zulkifly SB, Graham JM, Young EB, Mayer RJ, Flores CS, Piotrowski MJ, Smith BD, Graham LE. 2013. The genus Cladophora Kützing (Ulvophyceae) as a globally distributed ecological engineer. Journal of Phycology 49: 1-17. DOI: 10.1111/jpy.12025.

Choi CJ, Berges JA, Young EB. 2012. Rapid Effects of Diverse Toxic Water Pollutants on Chlorophyll a Fluorescence: Variable Responses Among Freshwater Microalgae. Water Research 46:2615-2626.

Mills JE, Meyer GA, Reinartz J, and Young EB. 2012. An exotic invasive shrub has greater recruitment than native shrubspecies within a large, undisturbed wetland. Plant Ecology213:1425-1436.

Zulkifly SB, Hanshew A, Young EB, Lee PO, Graham ME, Graham LE. 2012. The epiphytic microbiota of the globally widespread macroalga Cladophora (Chlorophyta, Cladphorales).American Journal of Botany 99: 1542-1553.

Xiao L, Young EB, Berges J, He J. 2012. Integrated Photo-Bioelectrochemical System for Contaminants Removal and Bioenergy Production. Environmental Science and Technology 46: 11459–11466. 

Young EB, Tucker RC,Pansch L. 2010. Alkaline Phosphatase in Freshwater Cladophora-Epiphyte Assemblages: Cell Specific Staining Conditions and Regulation in Response to Phosphorus Supply. Journal of Phycology 46: 93-101.

Mills JE, Reinartz J, Meyer GA, Young EB. 2009. Consequences of glossy buckthorn (Rhamnus frangula) invasion of a large wetland complex. Biological Invasions 11:1803-1820.

Young EB and Janssen J. 2009. Ecological processes across the salinity divide: Contrasts and comparisons in marine and Great Lakes ecosystems. Bulletin of the Ecological Society of America 90: 115-133.

Young EB, Berges JA and Dring MJ. 2009. Physiological responses of marine intertidal algae to N deprivation and resupply of nitrate and ammonium. Physiologia Plantarum, 135: 400–411. 

Bott T, Meyer GA, Young EB. 2008. Nutrient limitation and morphological plasticity of the carnivorous pitcher plant Sarracenia purpurea in contrasting wetland environments. New Phytologist. In Press.

Young, EB, Dring MJ, Berges JA. 2007. Distinct patterns of nitrate reductase activity in brown algae: light and ammonium sensitivity in Laminaria digitata is absent in Fucus species. J. Phycology. 43: 1200 – 1208.

Young EB, Dring MJ, Savidge G, Birkett DA. Berges JA. 2007 Seasonal variations in nitrate reductase activity and internal N pools in intertidal brown algae are correlated with ambient nitrate concentrations. Plant Cell and Environment 30: 764-774.

Young EB and Beardall J. 2005. Modulation of photosynthesis and inorganic carbon acquisition in a marine microalga by nitrogen, iron and light availability. Canadian Journal of Botany 83: 917-928. 

Young E, van Elven B, Lavery P, Berges J, Dring M. 2005. Inorganic nitrogen profiles in seagrass meadows and spatial patterns of nitrate reductase activity in macroalgal epiphytes.Marine Ecology Progress Series. 288: 103-114.

Young E and Beardall J. 2003. Photosynthetic function in Dunaliella tertiolecta during a nitrogen starvation and recovery cycle. Journal of Phycology 39: 897-905.

Young E and Beardall J. 2003. Transient perturbations in chlorophyll a fluorescence elicited by nitrogen re-supply to nitrogen-stressed microalgae: distinct responses to NO3- versus NH4+. Journal of Phycology 39: 332-342

Young E, Giordano M, Beardall J. 2001. Inorganic carbon acquisition by Dunaliella tertiolecta(Chlorophyta) involves external carbonic anhydrase and direct HCO3- utilisation (insensitive to the anion exchange inhibitor DIDS). European Journal of Phycology 36: 81-88.

Beardall J, Young E, Roberts S. 2001. Interactions between nutrient uptake and cellular metabolism: approaches for determining algal nutrient status. Aquatic Sciences. 63: 44-69.