SFS Annual Meeting

5/20/2019  |   14:00 - 14:15   |  151 ABC

NUTRIENTS (N, P, Fe) AND PHARMACEUTICALS (CAFFEINE, DIPHENHYDRAMINE) STRUCTURE THE CORE BACTERIAL COMMUNITY IN URBAN AND MONTANE STREAM BIOFILMS The core microbiome dramatically impacts freshwater stream biofilm formation, function and resilience to disturbance. Within biofilms, nutrient and pharmaceutical loading may impact structure and ultimately ecosystem function. To examine the effects of human activities, we evaluated bacterial community composition within biofilms growing on submerged nutrient (nitrogen, phosphorus, and iron) and pharmaceutical (caffeine and diphenhydramine) additions across montane and urban streams in three watersheds in northern Utah. The environmental conditions within urban streams acted as an environmental filter, reducing compositional differences among communities at urban sites. Nutrients and pharmaceuticals had subtle, yet functionally relevant impacts on the bacterial core. Nutrients enhanced dominance in core communities, increasing the relative abundance of Comamonadaceae (Betaproteobacteria) and Pseudomonadaceae (Gammaproteobacteria). Taxa dominance was potentially related to certain species rapidly exploiting excess nutrients. In contrast, pharmaceuticals fostered distinct and diverse communities, which included several contaminant-degrading taxa in the Sphingomonadaceae (Alphaproteobacteria) and Anaerolineaceae (Chloroflexi), suggesting the requirement of a more diverse community to degrade xenobiotics. Our results identify that anthropogenic chemical stressors may have unique ecosystem-level ramifications to stream environments.

Elizabeth Ogata (Primary Presenter/Author), Utah State University, bethogata@gmail.com;


Michelle Baker (Co-Presenter/Co-Author), Utah State University, michelle.baker@usu.edu;


Emma Rosi (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, rosie@caryinstitute.org;


Trevor Smart (Co-Presenter/Co-Author), Brigham Young University, tsmart4@gmail.com;


Donald Long (Co-Presenter/Co-Author), Southern Utah University, theinquisitor008@yahoo.com;


Zachary Aanderud (Co-Presenter/Co-Author), Brigham Young University, zachary_aanderud@byu.edu;


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5/20/2019  |   14:15 - 14:30   |  151 ABC

TRACING THE SOURCES, FATES, AND ACTIVITIES OF LEAF-ASSOCIATED MICROBES INTO THE STREAM FOOD WEB Quantitative stable isotope probing (qSIP) combined with high throughput sequencing provides a new tool for differentiating active versus inactive microbial taxa throughout leaf litter decomposition. Prior research has demonstrated this technique using 16S rRNA gene sequencing to differentiate active versus inactive bacterial and archeal taxa. We demonstratethat qSIP combined with sequencing the internal transcribed spacer region (ITS) of rRNA genes can be used to identify fungal taxa that are actively growing on decomposing leaves. We applied this approach to a litter decomposition experiment in which four leaf species were incubated in stream water for up to 24 days. Results show that most active fungi colonize with the leaf and that many fungal taxa are present but not active. Furthermore, bacteria colonize from the water column, and most are active. We also used qSIP to trace the fates of bacterial taxa ingested with leaf litter by a shredding caddisfly. We found evidence for 'gut specialists' that are active only when fed certain leaf types. Cottonwood gut specialists outnumber oak gut specialists.

Benjamin Koch (Primary Presenter/Author), Northern Arizona University, ben.koch@nau.edu;


Rebecca Fritz (Co-Presenter/Co-Author), Northern Arizona University, rjf227@nau.edu;


Michaela Hayer (Co-Presenter/Co-Author), Northern Arizona University, michaela.hayer@nau.edu;


Bruce Hungate (Co-Presenter/Co-Author), Northern Arizona University, bruce.hungate@nau.edu;


Egbert Schwartz (Co-Presenter/Co-Author), Northern Arizona University, egbert.schwartz@nau.edu;


Jane Marks (Co-Presenter/Co-Author), Northern Arizona University, jane.marks@nau.edu;


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5/20/2019  |   14:30 - 14:45   |  151 ABC

IS IT ALL ABOUT THE SLIME? UNDERSTANDING DENITRIFICATION AND PHARMACEUTICAL DYNAMICS IN WATER CHESTNUT (TRAPA) BEDS Pharmaceuticals have been detected in freshwater systems world-wide. Intrinsically biologically active, pharmaceuticals have the potential to act on non-target organisms at sub-lethal concentrations, including microbes that provide important ecosystem services. Shallow backwaters along the edge of the Hudson River (NY), a tidal freshwater river system, are densely vegetated with the invasive floating macrophyte Trapa natans. Trapa beds play an integral role in the Hudson River’s ecology due to their considerable capacity for denitrification, a microbially-mediated process that is vital for reducing eutrophication and harmful algal blooms. This study examines how several commonly used pharmaceuticals affect denitrifying microbial communities within the water column, root biofilm and sediment of Trapa beds. Pharmaceutical diffusing substrates (PhaDS) were used to expose biofilm microbial communities to an antibiotic (ciprofloxacin), an antidiabetic (metformin), and a histamine-2 blocker (ranitidine). Denitrification rates were measured as dinitrogen production using Membrane Inlet Mass Spectrometry, and microbial community structure was assessed with 16S profiling and whole genome metagenomics.

Rebekah Henry (Co-Presenter/Co-Author), Monash University, Rebekah.Henry@monash.edu;


Stephen Hamilton (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, hamilton@caryinstitute.org;


Emma Rosi (Co-Presenter/Co-Author), Cary Institute of Ecosystem Studies, rosie@caryinstitute.org;


David McCarthy (Co-Presenter/Co-Author), Monash University, david.mccarthy@monash.edu ;


Michael Grace (Co-Presenter/Co-Author), Monash University , michael.grace@monash.edu;


Cami Plum (Primary Presenter/Author), Monash University, cami.plum@monash.edu;


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5/20/2019  |   14:45 - 15:00   |  151 ABC

OXYGEN, PH, AND LABILE ORGANIC CARBON AS POSSIBLE MECHANISMS FOR ALGAL STIMULATION OF BACTERIAL AND FUNGAL PRODUCTION IN PERIPHYTON Previous studies have documented stimulation of periphytic microbial heterotrophs by algal photosynthesis, however the exact mechanisms for this stimulation remain unknown. We incubated submerged Typha domingensis leaf litter in greenhouse mesocosms under high and low dissolved nutrient regimes and conducted microbial production assays after 79 or 128 days of colonization. During these short-term assays, we manipulated environmental factors (oxygen, pH, and labile organic carbon) that can be altered by algal photosynthesis to test the hypothesis that one or more of these factors stimulates heterotrophic microbial production in periphyton communities. During the day 79 assays, fungal production was simulated by photosynthesis in the high nutrient treatment (p= 0.0009) and bacterial production was increased by glucose addition in the low nutrient treatment (p= 0.043). Analysis of day 128 assays is ongoing. Our preliminary results confirm that algal photosynthesis can increase heterotrophic microbial production, and suggest that photosynthetic labile organic carbon production could be a stimulatory mechanism. This research has the potential to identify the role of photosynthesis as a stimulator of ecosystem-level processes in aquatic ecosystems.

Kevin A. Kuehn (Co-Presenter/Co-Author), University of Southern Mississippi, kevin.kuehn@usm.edu;


Halvor Halvorson (Co-Presenter/Co-Author), University of Southern Mississippi, Halvor.Halvorson@usm.edu;


Robert Findlay (Co-Presenter/Co-Author), University of Alabama, rfindlay@ua.edu;


Steven Francoeur (Co-Presenter/Co-Author), Eastern Michigan University, sfrancoeu@emich.edu;


Jennifer Harper (Primary Presenter/Author), Biology Department, Eastern Michigan University, jharpe18@emich.edu;


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5/20/2019  |   15:00 - 15:15   |  151 ABC

CONTRASTING EFFECTS OF TWO MACROINVERTEBRATE CONSUMERS ON STREAM DETRITAL MICROBIAL BIOFILMS UNDER LIGHT MANIPULATION In lotic freshwater systems, aquatic macroinvertebrates are key processors of biofilms that grow upon organic matter. Although macroinvertebrate effects on biofilms may depend on light availability, the combined effects of consumers and light remain unexplored. Here, we conducted experiments to test effects of presence/absence of the omnivorous shrimp Macrobrachium ohione and the shredding caddisfly Pycnopsyche sp. on Liriodendron tulipifera litter biofilms in experimental streams under light or darkness. We measured litter-associated algal and bacterial production rates, as well as litter decomposition, over 49 days. Both experiments exhibited significant positive effects of light on algal productivity (P<0.001) and interactions of Macrobrachium and Pycnopsyche presence with time and light (P<0.05). Light increased bacterial productivity in the Pycnopsyche experiment (P<0.05) but not in the Macrobrachium experiment, in which time, light, and Macrobrachium interactively affected bacterial production (P<0.05). Litter decomposition was unaffected by light or Macrobrachium presence, but Pycnopsyche presence increased decomposition rates (P<0.05). Our results suggest that light strongly affects litter biofilms, whereas consumers primarily affect the timing of periphytic microbial colonization of organic matter. Compared to omnivores, shredder-detritivores may exert stronger effects on turnover and decomposition of organic material within lotic systems.

Cheyenne Brady (Primary Presenter/Author), University of Southern Mississippi, w864850@usm.edu;


Steve Francoeur (Co-Presenter/Co-Author), Biology Department, Eastern Michigan University, steve.francoeur@emich.edu;


Halvor Halvorson (Co-Presenter/Co-Author), University of Central Arkansas, hhalvorson@uca.edu;


Kevin A. Kuehn (Co-Presenter/Co-Author), University of Southern Mississippi, kevin.kuehn@usm.edu;


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5/20/2019  |   15:15 - 15:30   |  151 ABC

MORE BIOLOGICALLY AVAILABLE PHOSPHOROUS, LESS EUKARYOTIC GRAZER POPULATIONS, AND WARMER TEMPERATURES MAY INTENSIFY HABS ON UTAH LAKE The inception and persistence of harmful algal blooms (HABs) is linked to the appropriate conditions for a given cyanobacteria to become abundant. Certain cyanobacterial species may exploit nutrients, thrive under seasonal fluctuations in physicochemical lake conditions, and/or escape predation of eukaryotic grazers. To identify specific environmental conditions promoting individual HAB species, we tracked shifts in abundance of major cyanobacterial species in response to fluctuations in nutrient availability, top-down grazer pressure, and lake chemistry weekly through the spring and summer (May 5th – Oct 10th) of 2017 across seven sites on Utah Lake, USA. We found that 11 cyanobacterial operational taxonomic units across five genera (Aphanizomenon, Anabaena, Synechococcus, Microcystis, Planktothrix) contributed to HABs constituting anywhere from 4% to almost 50% of the total bacterial community in surface waters. Based on linear mixed effect models, HAB contributors were triggered by species-specific interactions with light availability, total Phosphorous, total dissolved Phosphorous, soluble reactive Phosphorous, water temperature, and three grazers (Genus: Copepoda, Cyclopoida, and Diplostraca). ). Our results indicate that HAB contributors are triggered by more biologically available phosphorus and higher temperatures that stimulate eukaryotic grazer populations.

Erin Jones (Co-Presenter/Co-Author), Brigham Young University, erinfjones3@gmail.com;


Neil Hansen (Co-Presenter/Co-Author), Brigham Young University, neil_hansen@byu.edu ;


Benjamin Abbott (Co-Presenter/Co-Author), Brigham Young University, Department of Plant and Wildlife Sciences, benabbott@byu.edu;


Greg Carling (Co-Presenter/Co-Author), Brigham Young University, greg.carling@byu.edu;


Michelle Baker (Co-Presenter/Co-Author), Utah State University, michelle.baker@usu.edu;


Scott Collins (Primary Presenter/Author,Co-Presenter/Co-Author), Brigham Young University, scottcollins333@gmail.com;


Zachary Aanderud (Co-Presenter/Co-Author), Brigham Young University, zachary_aanderud@byu.edu;


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