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Harmful algal blooms (HABs) frequently occur in eutrophic water bodies, which are often dominated by either non‐diazotrophic or diazotrophic strains of cyanobacteria. The occurrence of HABs is associated with multiple environmental factors that affect cyanobacterial growth, though adaptations of cyanobacteria to respond to diverse growing conditions are largely unknown. One factor affecting HAB persistence is the ability of cyanobacteria to synthesize and metabolize large biomolecules such as the light harvesting pigments phycobiliproteins that can also act as nitrogen (N) storage. Here, we examined how cyanobacteria varied phycobiliprotein content in response to different light intensity and N availability in two HAB forming species, Microcystis aeruginosa (non‐diazotrophic) and Dolichospermum flos‐aquae (diazotrophic). Our results revealed both HAB forming species responded similarly to light intensity, with decreasing light causing an increased production of phycobiliproteins, although at different rates. However, we observed dissimilar phycobiliprotein responses to varied N availability. In low N conditions, M. aeruginosa degraded phycobiliproteins primarily due to the decreased need for photosynthesis, whereas D. flos‐aquae, increased phycobiliproteins production under N‐limited conditions likely caused by the increased energetic requirements for N2‐fixation. Our results indicate that M. aeruginosa stored as much as 30% of cellular N in phycobiliproteins under high N conditions, while D. flos‐aquae only allocated 5% of the cellular N in phycobiliproteins. This study reveals a fundamental physiological difference between non‐diazotrophic and diazotrophic cyanobacteria, highlighting the critical role of phycobiliproteins on the persistence of cyanobacteria blooms under scenarios with varied light intensity and N availability.
Jingyu Wang; Nicole D. Wagner; James M. Fulton; J. Thad Scott. Diazotrophs modulate phycobiliproteins and nitrogen stoichiometry differently than other cyanobacteria in response to light and nitrogen availability. Limnology and Oceanography 2021, 66, 2333 -2345.
AMA StyleJingyu Wang, Nicole D. Wagner, James M. Fulton, J. Thad Scott. Diazotrophs modulate phycobiliproteins and nitrogen stoichiometry differently than other cyanobacteria in response to light and nitrogen availability. Limnology and Oceanography. 2021; 66 (6):2333-2345.
Chicago/Turabian StyleJingyu Wang; Nicole D. Wagner; James M. Fulton; J. Thad Scott. 2021. "Diazotrophs modulate phycobiliproteins and nitrogen stoichiometry differently than other cyanobacteria in response to light and nitrogen availability." Limnology and Oceanography 66, no. 6: 2333-2345.
The role of nitrogen (N) fixation in determining the frequency, magnitude, and extent of harmful algal blooms (HABs) has not been well studied. Dolichospermum is a common HAB species that is diazotrophic (capable of N fixation) and thus growth is often considered never to be limited by low combined N sources. However, N fixation is energetically expensive and its cost during bloom formation has not been quantified. Additionally, it is unknown how acclimation to differing nutrient ratios affects growth and cellular carbon (C):N stoichiometry. Here, we test the hypotheses that diazotrophic cyanobacteria are homeostatic for N because of their ability to fix atmospheric N2 and that previous acclimation to low N environments will result in more fixed N and lower C:N stoichiometry. Briefly, cultures that varied in resource N:phosphorus (P) ranging from 0.01 to 100 (atom), were seeded with Dolichospermum which were previously acclimated to low and high N:P conditions and then sampled temporally for growth and C:N stoichiometry. We found that Dolichospermum was not homeostatic for N and displayed classic signs of N limitation and elevated C:N stoichiometry, highlighting the necessary growth trade-off within cells when expending energy to fix N. Acclimation to N limited conditions caused differences in both C:N and fixed N at various time points in the experiment. These results highlight the importance of environmentally available N to a diazotrophic bloom, as well as how previous growth conditions can influence population growth during blooms experiencing variable N:P.
Felicia S. Osburn; Nicole D. Wagner; J. Thad Scott. Biological stoichiometry and growth dynamics of a diazotrophic cyanobacteria in nitrogen sufficient and deficient conditions. Harmful Algae 2021, 103, 102011 .
AMA StyleFelicia S. Osburn, Nicole D. Wagner, J. Thad Scott. Biological stoichiometry and growth dynamics of a diazotrophic cyanobacteria in nitrogen sufficient and deficient conditions. Harmful Algae. 2021; 103 ():102011.
Chicago/Turabian StyleFelicia S. Osburn; Nicole D. Wagner; J. Thad Scott. 2021. "Biological stoichiometry and growth dynamics of a diazotrophic cyanobacteria in nitrogen sufficient and deficient conditions." Harmful Algae 103, no. : 102011.
Harmful algal blooms (HABs) are increasing in magnitude, frequency, and duration caused by anthropogenic factors such as eutrophication and altered climatic regimes. While the concentrations and ratios of nitrogen (N) and phosphorus are correlated with bloom biomass and cyanotoxin production, there is less known about how N forms and micronutrients (MN) interact to regulate HABs and cyanotoxin production. Here, we used two separate approaches to examine how N and MN supply affects cyanobacteria biomass and cyanotoxin production. First, we used a Microcystis laboratory culture to examine how N and MN concentration and N form affected the biomass, particulate N, and microcystin-LR concentration and cell quotas. Then, we monitored the N, iron, molybdenum, and total microcystin concentrations from a hypereutrophic reservoir. From this hypereutrophic reservoir, we performed a community HAB bioassay to examine how N and MN addition affected the biomass, particulate N, and microcystin concentration. Microcystis laboratory cultures grown in high urea and MN conditions produced more biomass, particulate N, and had similar C:N stoichiometry, but lower microcystin-LR concentrations and cell quotas when compared to high nitrate and MN conditions. Our community HAB bioassay revealed no interactions between N concentration and MN addition caused by non-limiting MN background concentrations. Biomass, particulate N, and microcystin concentration increased with N addition. The community HAB amended with MN resulted in greater microcystin-LA concentration compared to non-MN amended community HABs. Our results highlight the complexity of how abiotic variables control biomass and cyanotoxin production in both laboratory cultures of Microcystis and community HABs.
Nicole D. Wagner; Emily Quach; Seth Buscho; Ashley Ricciardelli; Anupama Kannan; Sandi Win Naung; Grace Phillip; Berkeley Sheppard; Lauren Ferguson; Ashley Allen; Christopher Sharon; Jacquelyn R. Duke; Raegyn B. Taylor; Bradley J. Austin; Jasmine K. Stovall; Brian E. Haggard; C. Kevin Chambliss; Bryan W. Brooks; J. Thad Scott. Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms. Harmful Algae 2021, 103, 102002 .
AMA StyleNicole D. Wagner, Emily Quach, Seth Buscho, Ashley Ricciardelli, Anupama Kannan, Sandi Win Naung, Grace Phillip, Berkeley Sheppard, Lauren Ferguson, Ashley Allen, Christopher Sharon, Jacquelyn R. Duke, Raegyn B. Taylor, Bradley J. Austin, Jasmine K. Stovall, Brian E. Haggard, C. Kevin Chambliss, Bryan W. Brooks, J. Thad Scott. Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms. Harmful Algae. 2021; 103 ():102002.
Chicago/Turabian StyleNicole D. Wagner; Emily Quach; Seth Buscho; Ashley Ricciardelli; Anupama Kannan; Sandi Win Naung; Grace Phillip; Berkeley Sheppard; Lauren Ferguson; Ashley Allen; Christopher Sharon; Jacquelyn R. Duke; Raegyn B. Taylor; Bradley J. Austin; Jasmine K. Stovall; Brian E. Haggard; C. Kevin Chambliss; Bryan W. Brooks; J. Thad Scott. 2021. "Nitrogen form, concentration, and micronutrient availability affect microcystin production in cyanobacterial blooms." Harmful Algae 103, no. : 102002.
Many lakes across Canada and northern Europe have experienced declines in ambient phosphorus (P) and calcium (Ca) supply for over 20 years. While these declines might create or exacerbate nutrient limitation in aquatic food webs, our ability to detect and quantify different types of nutrient stress on zooplankton remains rudimentary. Here, we used growth bioassay experiments and whole transcriptome RNAseq, collectively nutrigenomics, to examine the nutritional phenotypes produced by low supplies of P and Ca separately and together in the freshwater zooplankter Daphnia pulex . We found that daphniids in all three nutrient-deficient categories grew slower and differed in their elemental composition. Our RNAseq results show distinct responses in singly limited treatments (Ca or P) and largely a mix of these responses in animals under low Ca and P conditions. Deeper investigation of effect magnitude and gene functional annotations reveals this patchwork of responses to cumulatively represent a co-limited nutritional phenotype. Linear discriminant analysis identified a significant separation between nutritional treatments based upon gene expression patterns with the expression patterns of just five genes needed to predict animal nutritional status with 99% accuracy. These data reveal how nutritional phenotypes are altered by individual and co-limitation of two highly important nutritional elements (Ca and P) and provide evidence that aquatic consumers can respond to limitation by more than one nutrient at a time by differentially altering their metabolism. This use of nutrigenomics demonstrates its potential to address many of the inherent complexities in studying interactions between multiple nutritional stressors in ecology and beyond.
Catriona L. C. Jones; Aaron B. A. Shafer; William D. Kim; Clay Prater; Nicole D. Wagner; Paul C. Frost. The complexity of co-limitation: nutrigenomics reveal non-additive interactions of calcium and phosphorus on gene expression in Daphnia pulex. Proceedings of the Royal Society B: Biological Sciences 2020, 287, 20202302 .
AMA StyleCatriona L. C. Jones, Aaron B. A. Shafer, William D. Kim, Clay Prater, Nicole D. Wagner, Paul C. Frost. The complexity of co-limitation: nutrigenomics reveal non-additive interactions of calcium and phosphorus on gene expression in Daphnia pulex. Proceedings of the Royal Society B: Biological Sciences. 2020; 287 (1941):20202302.
Chicago/Turabian StyleCatriona L. C. Jones; Aaron B. A. Shafer; William D. Kim; Clay Prater; Nicole D. Wagner; Paul C. Frost. 2020. "The complexity of co-limitation: nutrigenomics reveal non-additive interactions of calcium and phosphorus on gene expression in Daphnia pulex." Proceedings of the Royal Society B: Biological Sciences 287, no. 1941: 20202302.
Harmful algal blooms (HABs) are increasing in magnitude, frequency, and duration globally. Even though a limited number of phytoplankton species can be toxic, they are becoming one of the greatest water quality threats to public health and ecosystems due to their intrinsic toxicity to humans and the numerous interacting factors that undermine HAB forecasting. Here, we show that the carbon:nitrogen:phosphorus (C:N:P) stoichiometry of a common toxic phytoplankton species, Microcystis, regulates toxin quotas during blooms through a tradeoff between primary and secondary metabolism. Populations with optimal C:N (< 8) and C:P (< 200) cellular stoichiometry consistently produced more toxins than populations exhibiting stoichiometric plasticity. Phosphorus availability in water exerted a strong control on population biomass and C:P stoichiometry, but N availability exerted a stronger control on toxin quotas by regulating population biomass and C:N:P stoichiometry. Microcystin-LR, like many phytoplankton toxins, is an N-rich secondary metabolite with a C:N stoichiometry that is similar to the optimal growth stoichiometry of Microcystis. Thus, N availability relative to P and light provides a dual regulatory mechanism that controls both biomass production and cellular toxin synthesis. Overall, our results provide a quantitative framework for improving forecasting of toxin production during HABs and compelling support for water quality management that limit both N and P inputs from anthropogenic sources.
Nicole D. Wagner; Felicia S. Osburn; Jingyu Wang; Raegyn Taylor; Ashlynn R. Boedecker; C. Kevin Chambliss; Bryan W. Brooks; J. Thad Scott. Biological Stoichiometry Regulates Toxin Production in Microcystis aeruginosa (UTEX 2385). Toxins 2019, 11, 601 .
AMA StyleNicole D. Wagner, Felicia S. Osburn, Jingyu Wang, Raegyn Taylor, Ashlynn R. Boedecker, C. Kevin Chambliss, Bryan W. Brooks, J. Thad Scott. Biological Stoichiometry Regulates Toxin Production in Microcystis aeruginosa (UTEX 2385). Toxins. 2019; 11 (10):601.
Chicago/Turabian StyleNicole D. Wagner; Felicia S. Osburn; Jingyu Wang; Raegyn Taylor; Ashlynn R. Boedecker; C. Kevin Chambliss; Bryan W. Brooks; J. Thad Scott. 2019. "Biological Stoichiometry Regulates Toxin Production in Microcystis aeruginosa (UTEX 2385)." Toxins 11, no. 10: 601.
Consumer products such as perfluorooctanesulfonic acid (PFOS) and pharmaceuticals (PCPPs) enter aquatic ecosystems through inefficient removal during wastewater treatment. Often, the sterilization process of wastewater includes the addition of sodium hypochlorite that can react with PCPPs and other organic matter (i.e., dissolve organic matter) to generate disinfection by-products and can cause the final effluent to be more harmful to aquatic organisms. Here, we exposed Daphnia magna to two stages of wastewater, the pre-chlorinated wastewater (PreCl) and the final effluent. In addition, we exposed D. magna, to the final effluent with a concentration gradient of added PFOS, to investigate if this persistent contaminant altered the toxicity of the final effluent. After 48 h of contaminant exposure, we measured the daphnids metabolic responses to the different stages of wastewater treatment, and with the addition of PFOS, utilizing proton nuclear magnetic resonance spectroscopy and liquid chromatography tandem mass spectrometry. We found few significant changes to the metabolic profile of animals exposed to the PreCl wastewater; however, animals exposed to the final effluent displayed increases in many amino acids and decreases in some sugar metabolites. With the addition of PFOS to the final effluent, the metabolic profile shifted from increased amino acids and decreased sugar metabolites and energy molecules especially at the low and high concentrations of PFOS. Overall, our results demonstrate the metabolome is sensitive to changes in the final effluent that are caused by sterilization, and with the addition of a persistent contaminant, the metabolic profile is further altered.
Nicole D. Wagner; Paul A. Helm; André J. Simpson; Myrna J. Simpson. Metabolomic responses to pre-chlorinated and final effluent wastewater with the addition of a sub-lethal persistent contaminant in Daphnia magna. Environmental Science and Pollution Research 2019, 26, 9014 -9026.
AMA StyleNicole D. Wagner, Paul A. Helm, André J. Simpson, Myrna J. Simpson. Metabolomic responses to pre-chlorinated and final effluent wastewater with the addition of a sub-lethal persistent contaminant in Daphnia magna. Environmental Science and Pollution Research. 2019; 26 (9):9014-9026.
Chicago/Turabian StyleNicole D. Wagner; Paul A. Helm; André J. Simpson; Myrna J. Simpson. 2019. "Metabolomic responses to pre-chlorinated and final effluent wastewater with the addition of a sub-lethal persistent contaminant in Daphnia magna." Environmental Science and Pollution Research 26, no. 9: 9014-9026.
Anthropogenic activity is increasing the presence of contaminants that enter waterways through wastewater effluent and urban and/or agricultural runoff, generally in complex mixtures. Depending on the mode of action of the individual contaminant within the mixture, toxicity can occur due to contaminants having similar or dissimilar modes of action. However, it is unknown how the metabolome responds to sub‐lethal contaminant mixtures in the keystone genus, Daphnia. Here we examined D. magna metabolic responses to acute sub‐lethal exposure of propranolol (PRO), carbamazepine (CBZ), and perfluorooctanesulfonic acid (PFOS) as well as in binary (PRO‐CBZ, PRO‐PFOS, CBZ‐PFOS) and tertiary mixtures (CBZ‐PRO‐PFOS); all at 10% of the median lethal concentration of the population (LC50). The metabolome was measured using 1H nuclear magnetic resonance (NMR) and characterized using principal component analysis (PCA), regression analysis and fold changes in metabolite relative to the unexposed (control) group. The averaged PCA scores plots revealed CBZ‐PFOS and CBZ‐PRO‐PFOS exposures were significantly different from the control treatment. After normalizing the toxicity of each contaminant, we found that some metabolites responded monotonically, while others displayed a non‐monotonic response with increasing toxicity units. The single contaminant exposures and two binary mixtures (PRO‐CBZ, and PRO‐PFOS) resulted in minimal changes in the identified metabolites whereas, the CBZ‐PFOS and CBZ‐PRO‐PFOS displayed increases in several amino acid metabolites and decreases in glucose. Overall, our results highlight the sensitivity of the metabolome to distinguish the composition of the contaminant mixtures with some mixtures displaying heightened responses versus others. This article is protected by copyright. All rights reserved
Nicole D. Wagner; André J. Simpson; Myrna J. Simpson. Sublethal metabolic responses to contaminant mixture toxicity in Daphnia magna. Environmental Toxicology and Chemistry 2018, 37, 2448 -2457.
AMA StyleNicole D. Wagner, André J. Simpson, Myrna J. Simpson. Sublethal metabolic responses to contaminant mixture toxicity in Daphnia magna. Environmental Toxicology and Chemistry. 2018; 37 (9):2448-2457.
Chicago/Turabian StyleNicole D. Wagner; André J. Simpson; Myrna J. Simpson. 2018. "Sublethal metabolic responses to contaminant mixture toxicity in Daphnia magna." Environmental Toxicology and Chemistry 37, no. 9: 2448-2457.
The growth of animal consumers is affected by the balance of elements in their diet with the transition between limitation by one element to another known as the threshold elemental ratio (TER). Precise estimates of TERs with known levels of uncertainty have yet to be generated for most zooplankton consumers. We determined the TER for carbon (C) and phosphorus (P) in for a common lake zooplankter, Daphnia magna, using experimental measurements and theoretical considerations. Daphnia growth responses to food C:P ratios across a relatively narrow range (80-350) generated an empirical estimate of TERC:P of 155 ± 14. While this TER matched our modelled estimate of TERC:P (155 ± 16), it was lower than previous estimates of this dietary transition point. No threshold was found when we examined daphnid body C:N or C:P ratios in response to changing food C:P ratios, which indicates P-limitation at even lower food C:P ratios. Our results provide strong evidence that D. magna is likely to experience acute P-limitation when food C:P ratios exceed even relatively low ratios (~155). Our model further demonstrated that while physiological adjustments may reduce the likelihood of P-limitation or reduce its intensity, these changes in animal material processing would be accompanied by reduced maximum growth rates.
Hamza K. Khattak; Clay Prater; Nicole D. Wagner; Paul C. Frost. The threshold elemental ratio of carbon and phosphorus of Daphnia magna and its connection to animal growth. Scientific Reports 2018, 8, 9673 .
AMA StyleHamza K. Khattak, Clay Prater, Nicole D. Wagner, Paul C. Frost. The threshold elemental ratio of carbon and phosphorus of Daphnia magna and its connection to animal growth. Scientific Reports. 2018; 8 (1):9673.
Chicago/Turabian StyleHamza K. Khattak; Clay Prater; Nicole D. Wagner; Paul C. Frost. 2018. "The threshold elemental ratio of carbon and phosphorus of Daphnia magna and its connection to animal growth." Scientific Reports 8, no. 1: 9673.
In vivo nuclear magnetic resonance (NMR) spectroscopy is a particularly powerful technique, since it allows samples to be analyzed in their natural, unaltered state, criteria paramount for living organisms. In this study, a novel continuous low-volume flow system, suitable for in vivo NMR metabolomics studies, is demonstrated. The system allows for improved locking, shimming and water suppression, as well as allowing the use of trace amounts of expensive toxic contaminants or low volume of precious natural environmental samples as stressors. The use of double pump design with a sump slurry pump return, allows algal food suspensions to be continually supplied without the need for filters, eliminating the possibility of clogging and leaks. Using the flow-system, the living organism can be kept alive without stress indefinitely. To evaluate the feasibility and applicability of the flow system, changes in the metabolite profile of 13C enriched Daphnia magna over a 24-hour period are compared when feeding laboratory food vs. exposing them to a natural algal bloom sample. Clear metabolic changes are observed over a range of metabolites including, carbohydrates, lipids, amino acids and a nucleotide demonstrating in vivo NMR as a powerful tool to monitor environmental stress. The particular bloom used here was low in microcystins and the metabolic stress impacts are consistent with the bloom being a poor food source forcing the Daphnia to utilize their own energy reserves.
Maryam Tabatabaei Anaraki; Rudraksha Dutta Majumdar; Nicole Wagner; Ronald Soong; Vera Kovacevic; Eric J. Reiner; Satyendra P. Bhavsar; Xavier Ortiz Almirall; Daniel Lane; Myrna J. Simpson; Hermann Heumann; Sebastian Schmidt; André J. Simpson. Development and Application of a Low-Volume Flow System for Solution-State in Vivo NMR. Analytical Chemistry 2018, 90, 7912 -7921.
AMA StyleMaryam Tabatabaei Anaraki, Rudraksha Dutta Majumdar, Nicole Wagner, Ronald Soong, Vera Kovacevic, Eric J. Reiner, Satyendra P. Bhavsar, Xavier Ortiz Almirall, Daniel Lane, Myrna J. Simpson, Hermann Heumann, Sebastian Schmidt, André J. Simpson. Development and Application of a Low-Volume Flow System for Solution-State in Vivo NMR. Analytical Chemistry. 2018; 90 (13):7912-7921.
Chicago/Turabian StyleMaryam Tabatabaei Anaraki; Rudraksha Dutta Majumdar; Nicole Wagner; Ronald Soong; Vera Kovacevic; Eric J. Reiner; Satyendra P. Bhavsar; Xavier Ortiz Almirall; Daniel Lane; Myrna J. Simpson; Hermann Heumann; Sebastian Schmidt; André J. Simpson. 2018. "Development and Application of a Low-Volume Flow System for Solution-State in Vivo NMR." Analytical Chemistry 90, no. 13: 7912-7921.
Food quality and temperature can affect zooplankton production in lakes by altering organismal metabolism. However, the influence of these factors on consumer nutritional physiology and population biomass remains relatively understudied in natural populations. Here, we examined seasonal changes in body stoichiometry, biochemistry, and population biomass in two Daphnia species collected from two separate lakes differing in dietary phosphorus (P) supply. Food quality, measured as seston carbon:P (C:P) ratios, varied throughout the study in each lake, and water temperatures generally increased across the growing season. Daphnid elemental composition was correlated with food quality in both populations, but relationships between daphnid body stoichiometry and temperature were consistently stronger as Daphnia body C:P ratios and content of major biochemical pools declined simultaneously throughout the summer, which largely coincided with increased water temperatures. Warmer temperatures were associated with relaxed %P‐RNA coupling as daphnid body RNA content declined and P content remained relatively high. These responses combined with temperature related decreases in Daphnia body %lipids and %C appeared to explain declines in daphnid body C:P ratios in both lakes over the growing season. Seasonal changes in population biomass were related to both food quality and water temperature in the lower nutrient lake. Biomass production under more eutrophic conditions however was unrelated to food quality and was instead associated with seasonal temperature changes in the higher nutrient lake. Overall, our study shows that seasonal changes in temperature and resource quality may differentially affect consumer stoichiometry and biomass production in lake ecosystems by altering consumer elemental metabolism.
Clay Prater; Nicole Wagner; Paul C. Frost. Seasonal effects of food quality and temperature on body stoichiometry, biochemistry, and biomass production in Daphnia populations. Limnology and Oceanography 2018, 63, 1727 -1740.
AMA StyleClay Prater, Nicole Wagner, Paul C. Frost. Seasonal effects of food quality and temperature on body stoichiometry, biochemistry, and biomass production in Daphnia populations. Limnology and Oceanography. 2018; 63 (4):1727-1740.
Chicago/Turabian StyleClay Prater; Nicole Wagner; Paul C. Frost. 2018. "Seasonal effects of food quality and temperature on body stoichiometry, biochemistry, and biomass production in Daphnia populations." Limnology and Oceanography 63, no. 4: 1727-1740.
Nanobiotechnology has played important roles in solving contemporary health problems, including cancer and diabetes, but has not yet been widely exploited for problems in food security and environmental protection. Water scarcity is an emerging worldwide problem as a result of climate change and population increase. Current methods of managing water resources are not efficient or sustainable. In this perspective, we focus on harmful algal blooms to demonstrate how nanobiotechnology can be explored to understand microbe–environment interactions and allow for toxin/pollutant detection with significantly improved sensitivity. These capabilities hold potential for future development of sustainable solutions for drinking water management.
Matthew R. Gellert; Beum Jun Kim; Samuel E. Reffsin; Sebastian E. Jusuf; Nicole D. Wagner; Stephen C. Winans; Mingming Wu. Nanobiotechnology for the Environment: Innovative Solutions for the Management of Harmful Algal Blooms. Journal of Agricultural and Food Chemistry 2017, 66, 6474 -6479.
AMA StyleMatthew R. Gellert, Beum Jun Kim, Samuel E. Reffsin, Sebastian E. Jusuf, Nicole D. Wagner, Stephen C. Winans, Mingming Wu. Nanobiotechnology for the Environment: Innovative Solutions for the Management of Harmful Algal Blooms. Journal of Agricultural and Food Chemistry. 2017; 66 (26):6474-6479.
Chicago/Turabian StyleMatthew R. Gellert; Beum Jun Kim; Samuel E. Reffsin; Sebastian E. Jusuf; Nicole D. Wagner; Stephen C. Winans; Mingming Wu. 2017. "Nanobiotechnology for the Environment: Innovative Solutions for the Management of Harmful Algal Blooms." Journal of Agricultural and Food Chemistry 66, no. 26: 6474-6479.
Food quality is highly dynamic within lake ecosystems and varies spatially and temporally over the growing season. Consumers may need to continuously adjust their metabolism in response to this variation in dietary nutrient content. However, the rate of metabolic responses to changes in food nutrient content has received little direct study. Here, we examine responses in two metabolic phosphorus (P) pools, ribonucleic acids (RNA), and adenosine triphosphate (ATP) along with body mass and body P content in Daphnia magna exposed to chronic and acute dietary P-limitation. First, we examined food quality effects on animals consuming different food carbon (C):P quality over a 14 day period. Then, we raised daphnids on one food quality for 4 days, switched them to contrasting dietary treatments, and measured changes in their metabolic responses at shorter time-scales (over 48 h). Animal P, RNA, and ATP content all changed through ontogeny with adults containing relatively less of these pools with increasing body mass. Irrespective of age, Daphnia consuming high C:P diets had lower body %P, %RNA, %ATP, and mass compared to animals eating low C:P diets. Diet switching experiments revealed diet dependent changes in body %P, %RNA, %ATP, and animal mass within 48 hours. We found that Daphnia switched from low to high C:P diets had some metabolic buffering capacity with decreases in body %P occurring after 24 h but mass remaining similar to initial diet conditions for 36 h after the diet switch. Switching Daphnia from low to high C:P diets caused a decrease in the RNA:P ratio after 48 h. Daphnia switched from high to low C:P diets increased their body P, RNA, and ATP content within 8-24 h. This switch from high to low C:P diets also led to increased RNA:P ratios in animal bodies. Overall, our study revealed that consumer P metabolism reflects both current and past diet due to more dynamic and rapid changes in P biochemistry than total body mass. This metabolic flexibility is likely linked to resource integration in D. magna, which reduces the negative effects of short-term or variable exposure to nutrient-deficient foods.
Nicole D. Wagner; Clay Prater; Paul C. Frost. Dynamic Responses of Phosphorus Metabolism to Acute and Chronic Dietary Phosphorus-Limitation in Daphnia. Frontiers in Environmental Science 2017, 5, 1 .
AMA StyleNicole D. Wagner, Clay Prater, Paul C. Frost. Dynamic Responses of Phosphorus Metabolism to Acute and Chronic Dietary Phosphorus-Limitation in Daphnia. Frontiers in Environmental Science. 2017; 5 ():1.
Chicago/Turabian StyleNicole D. Wagner; Clay Prater; Paul C. Frost. 2017. "Dynamic Responses of Phosphorus Metabolism to Acute and Chronic Dietary Phosphorus-Limitation in Daphnia." Frontiers in Environmental Science 5, no. : 1.
Consumer body stoichiometry is a key trait that links organismal physiology to population and ecosystem-level dynamics. However, as elemental composition has traditionally been considered to be constrained within a species, the ecological and evolutionary factors shaping consumer elemental composition have not been clearly resolved. To this end, we examined the causes and extent of variation in the body phosphorus (P) content and the expression of P-linked traits, mass specific growth rate (MSGR), and P use efficiency (PUE) of the keystone aquatic consumer Daphnia using lake surveys and common garden experiments. While daphnid body %P was relatively constrained in field assemblages sampled across an environmental P gradient, unique genotypes isolated from these lakes showed highly variable phenotypic responses when raised across dietary P gradients in the laboratory. Specifically, we observed substantial inter- and intra-specific variation and differences in daphnid responses within and among our study lakes. While variation in Daphnia body %P was mostly due to plastic phenotypic changes, we documented considerable genetic differences in daphnid MSGR and PUE, and relationships between MSGR and body P content were highly variable among genotypes. Overall, our study found that consumer responses to food quality may differ considerably among genotypes and that relationships between organismal life-history traits and body stoichiometry may be strongly influenced by genetic and environmental variation in natural assemblages.
Clay Prater; Paul C. Frost; Nicole D. Wagner. Interactive effects of genotype and food quality on consumer growth rate and elemental content. Ecology 2017, 98, 1399 -1408.
AMA StyleClay Prater, Paul C. Frost, Nicole D. Wagner. Interactive effects of genotype and food quality on consumer growth rate and elemental content. Ecology. 2017; 98 (5):1399-1408.
Chicago/Turabian StyleClay Prater; Paul C. Frost; Nicole D. Wagner. 2017. "Interactive effects of genotype and food quality on consumer growth rate and elemental content." Ecology 98, no. 5: 1399-1408.
The use of consumer products and pharmaceuticals that act as contaminants entering waterways through runoff and wastewater effluents alters aquatic ecosystem health. Traditional toxicological endpoints may underestimate the toxicity of contaminants, as lethal concentrations are often orders of magnitude higher than those found within freshwater ecosystems. While newer techniques examine the metabolic responses of sublethal contaminant exposure, there has been no direct comparison with ontogeny in Daphnia. It was hypothesized that Daphnia magna would have distinct metabolic changes after 3 different sublethal contaminant exposures, because of differences in the toxic mode of action and ontogeny. To test this hypothesis, the proton nuclear magnetic resonance metabolomic profiles were measured in D. magna aged day 0 and 18 after exposure to 28% of the lethal concentration of 50% of organisms tested (LC50) of atrazine, propranolol, and perfluorooctanesulfonic acid (PFOS) for 48 h. Principal component analysis revealed significant separation of contaminants from the control daphnids in both neonates and adults exposed to propranolol and PFOS. In contrast, atrazine exposure caused separation from the controls in only the adult D. magna. Minimal ontogenetic changes in the targeted metabolites were seen after exposure to propranolol. For both atrazine and PFOS exposures ontogeny exhibited unique changes in the targeted metabolites. These results indicate that, depending on the contaminant studied, neonates and adults respond uniquely to sublethal contaminant exposure. Environ Toxicol Chem 2016;9999:1–9. © 2016 SETAC
Nicole Wagner; André J. Simpson; Myrna Simpson. Metabolomic responses to sublethal contaminant exposure in neonate and adultDaphnia magna. Environmental Toxicology and Chemistry 2016, 36, 938 -946.
AMA StyleNicole Wagner, André J. Simpson, Myrna Simpson. Metabolomic responses to sublethal contaminant exposure in neonate and adultDaphnia magna. Environmental Toxicology and Chemistry. 2016; 36 (4):938-946.
Chicago/Turabian StyleNicole Wagner; André J. Simpson; Myrna Simpson. 2016. "Metabolomic responses to sublethal contaminant exposure in neonate and adultDaphnia magna." Environmental Toxicology and Chemistry 36, no. 4: 938-946.
1.The role of nutrition in linking animals with their environment is increasingly seen as fundamental to explain ecological interactions. 2.The two currently predominant frameworks for exploring questions in nutritional ecology—Nutritional Geometry (NG) and Ecological Stoichiometry (ES)—share common features, but also differ in their goals and origins. NG originates from behavioural ecology using terrestrial insects as model organisms in tightly controlled feeding experiments, while ES originates from biogeochemistry focusing on the transfer of key elements across trophic levels, mainly in aquatic environments. 3.Here, we review the history of these two complementary frameworks, emphasizing the key concepts defining their respective aims, methodologies, and focal taxa to answer questions at different ecological scales. 4.We identify and explore homeostasis as a shared conceptual cornerstone of each framework that can be used to bridge knowledge gaps and for developing new hypotheses within nutritional ecology. 5.Expanding on the concept of homeostasis, we introduce dynamic energy budget (DEB) models as a general way to address homeostatic regulation at its fundamental level. 6.Specifically, we describe how a two-reserve DEB model can be used to track metabolic pathways of nutrients as well as elements and suggest that multi-reserve DEB models, when integrated and parameterized with NG and ES concepts, can form powerful components of agent-based models to predict how animal nutrition influences individual and trophic interactions in food webs. This article is protected by copyright. All rights reserved.
Erik Sperfeld; Nicole Wagner; Halvor M. Halvorson; Matthew Malishev; David Raubenheimer. Bridging Ecological Stoichiometry and Nutritional Geometry with homeostasis concepts and integrative models of organism nutrition. Functional Ecology 2016, 31, 286 -296.
AMA StyleErik Sperfeld, Nicole Wagner, Halvor M. Halvorson, Matthew Malishev, David Raubenheimer. Bridging Ecological Stoichiometry and Nutritional Geometry with homeostasis concepts and integrative models of organism nutrition. Functional Ecology. 2016; 31 (2):286-296.
Chicago/Turabian StyleErik Sperfeld; Nicole Wagner; Halvor M. Halvorson; Matthew Malishev; David Raubenheimer. 2016. "Bridging Ecological Stoichiometry and Nutritional Geometry with homeostasis concepts and integrative models of organism nutrition." Functional Ecology 31, no. 2: 286-296.
Erik Sperfeld; Halvor M. Halvorson; Matthew Malishev; Fiona J. Clissold; Nicole Wagner. Woodstoich III: Integrating tools of nutritional geometry and ecological stoichiometry to advance nutrient budgeting and the prediction of consumer‐driven nutrient recycling. Oikos 2016, 125, 1539 -1553.
AMA StyleErik Sperfeld, Halvor M. Halvorson, Matthew Malishev, Fiona J. Clissold, Nicole Wagner. Woodstoich III: Integrating tools of nutritional geometry and ecological stoichiometry to advance nutrient budgeting and the prediction of consumer‐driven nutrient recycling. Oikos. 2016; 125 (11):1539-1553.
Chicago/Turabian StyleErik Sperfeld; Halvor M. Halvorson; Matthew Malishev; Fiona J. Clissold; Nicole Wagner. 2016. "Woodstoich III: Integrating tools of nutritional geometry and ecological stoichiometry to advance nutrient budgeting and the prediction of consumer‐driven nutrient recycling." Oikos 125, no. 11: 1539-1553.
Zooplankton frequently face dietary limitation caused by imbalances between their nutrient requirements and the nutrient content of their phytoplankton food. While insufficient nutrition is acknowledged to affect growth and reproduction of zooplankton, the effect of dietary limitation on other aspects of their metabolism remains poorly studied. One understudied biochemical response associated with nutrient stress is changes to the free amino acid (FAA) composition of body tissues resulting from changes in dietary supply. We examined changes in FAA composition in two cladoceran species (Daphnia magna and Daphnia pulex) in response to stress created by ecologically relevant food conditions: low food quantities, high algal carbon: nitrogen (C:N) ratios, and high algal C: phosphorus (P) ratios. We measured 14 FAA after extracting them from lyophilized whole Daphnia grown under these contrasting algal diets. Generally, low food quantity and low algal P increased body FAA content in both daphnid species while many essential FAA decreased due to N-limitation. While significant responses to diet were seen for each daphnid species, the nature of these responses depended on the type of nutritional stress, the FAA examined, and on the species. Non-parametric discriminant analysis exhibited a high predictive ability to classify unknown zooplankton into the correct diet category. The observed changes in body FAA profiles of Daphnia illustrate strong effects that algal food quality can have on the biochemistry of planktonic consumers. Furthermore these results demonstrate body FAA composition of zooplankton may provide an important source of information about zooplankton nutrient limitation especially combined with other nutrient-dependent molecular responses.
Nicole D. Wagner; Zhen Yang; Andrew B. Scott; Paul C. Frost. Effects of algal food quality on free amino acid metabolism of Daphnia. Aquatic Sciences 2016, 79, 127 -137.
AMA StyleNicole D. Wagner, Zhen Yang, Andrew B. Scott, Paul C. Frost. Effects of algal food quality on free amino acid metabolism of Daphnia. Aquatic Sciences. 2016; 79 (1):127-137.
Chicago/Turabian StyleNicole D. Wagner; Zhen Yang; Andrew B. Scott; Paul C. Frost. 2016. "Effects of algal food quality on free amino acid metabolism of Daphnia." Aquatic Sciences 79, no. 1: 127-137.
Declines in environmental calcium (Ca) and phosphorus (P) concentrations have occurred over the past 30 yrs in lakes across the Canadian Shield in southern Ontario, and these reductions appear to be placing strong constraints on populations of Daphnia in this region. Here, we report results from a factorial manipulation of Ca concentrations and food P content under controlled laboratory conditions where we measured resulting changes in daphnid elemental content, individual growth and survival, and life history traits related to population growth. We found significant effects of Ca- and P-limitation on all variables measured; however, dietary P explained a majority of the variation in daphnid nutrient content and growth. Dietary effects of low P [high food carbon (C): P ratios] on individual Daphnia life-history traits also translated into significant population level effects. Dietary P also explained relatively more experimental variation in population level responses than Ca concentrations. Experimental Ca concentrations most strongly altered daphnid survival partly due to the use of a lethally low Ca concentration in our experiment. Although recent work examining shifts in zooplankton communities in this region mainly focuses on the effects of Ca-limitation, we show that Ca concentrations and food nutrient content, at levels commonly found on the Canadian Shield, are both likely to strongly alter Daphnia life-history and populations dynamics. Our results underscore the need to more fully examine how multielemental limitation (e.g., Ca, N, P) affects consumer physiology and life-history given the plausible translation of these effects on the community structure of lake zooplankton.
Clay Prater; Nicole Wagner; Paul C. Frost. Effects of calcium and phosphorus limitation on the nutritional ecophysiology of D aphnia. Limnology and Oceanography 2015, 61, 268 -278.
AMA StyleClay Prater, Nicole Wagner, Paul C. Frost. Effects of calcium and phosphorus limitation on the nutritional ecophysiology of D aphnia. Limnology and Oceanography. 2015; 61 (1):268-278.
Chicago/Turabian StyleClay Prater; Nicole Wagner; Paul C. Frost. 2015. "Effects of calcium and phosphorus limitation on the nutritional ecophysiology of D aphnia." Limnology and Oceanography 61, no. 1: 268-278.
Poor diet quality frequently constrains the growth and reproduction of primary consumers, altering their population dynamics, interactions in food webs, and contributions to ecosystem services such as nutrient cycling. The identification and measurement of an animal's nutritional state are thus central to studying the connections between diet and animal ecology. Here we show how the nutritional state of a freshwater invertebrate, Daphnia magna, can be determined by analyzing its endogenous metabolites using hydrogen nuclear magnetic resonance-based metabolomics. With a multivariate analysis, we observed the differentiation of the metabolite composition of animals grown under control conditions (good food and no environmental stress), raised on different diets (low quantity, nitrogen limited, and phosphorus limited), and exposed to two common environmental stressors (bacterial infection and salt stress). We identified 18 metabolites that were significantly different between control animals and at least one limiting food type or environmental stressor. The unique metabolite responses of animals caused by inadequate nutrition and environmental stress are reflective of dramatic and distinctive effects that each stressor has on animal metabolism. Our results suggest that dietary-specific induced changes in metabolite composition of animal consumers hold considerable promise as indicators of nutritional stress and will be invaluable to future studies of animal nutrition.
Nicole Wagner; Brian P. Lankadurai; Myrna Simpson; Andre J. Simpson; Paul C. Frost. Metabolomic Differentiation of Nutritional Stress in an Aquatic Invertebrate. Physiological and Biochemical Zoology 2015, 88, 43 -52.
AMA StyleNicole Wagner, Brian P. Lankadurai, Myrna Simpson, Andre J. Simpson, Paul C. Frost. Metabolomic Differentiation of Nutritional Stress in an Aquatic Invertebrate. Physiological and Biochemical Zoology. 2015; 88 (1):43-52.
Chicago/Turabian StyleNicole Wagner; Brian P. Lankadurai; Myrna Simpson; Andre J. Simpson; Paul C. Frost. 2015. "Metabolomic Differentiation of Nutritional Stress in an Aquatic Invertebrate." Physiological and Biochemical Zoology 88, no. 1: 43-52.
The nutritional history of an organism is often difficult to ascertain. Nonetheless, this information on past diet can be particularly important when explaining the role of nutrition in physiological responses and ecological dynamics. One approach to infer the past dietary history of an individual is through characterization of its nutritional phenotype, an interrelated set of molecular and physiological properties that are sensitive to dietary stress. Comparisons of nutritional phenotypes between a study organism and reference phenotypes have the potential to provide insight into the type and intensity of past dietary constraints. Here, we describe this process of nutritional profiling for ecophysiological research in which a suite of molecular and physiological responses are cataloged for animals experiencing known types and intensities of dietary stress and are quantitatively compared with those of unknown individuals. We supplement this delineation of the process of nutritional profiling with a first-order analysis of its sensitivity to the number of response variables in the reference database, their responsiveness to diet, and the size of reference populations. In doing so, we demonstrate the considerable promise this approach has to transform future studies of nutrition by its ability to provide more and better information on responses to dietary stress in animals and their populations.
P. C. Frost; K. Song; N. D. Wagner. A Beginner's Guide to Nutritional Profiling in Physiology and Ecology. Integrative and Comparative Biology 2014, 54, 873 -879.
AMA StyleP. C. Frost, K. Song, N. D. Wagner. A Beginner's Guide to Nutritional Profiling in Physiology and Ecology. Integrative and Comparative Biology. 2014; 54 (5):873-879.
Chicago/Turabian StyleP. C. Frost; K. Song; N. D. Wagner. 2014. "A Beginner's Guide to Nutritional Profiling in Physiology and Ecology." Integrative and Comparative Biology 54, no. 5: 873-879.