15 results on '"Abigail T. Farmer"'
Search Results
2. Urea Is Both a Carbon and Nitrogen Source for Microcystis aeruginosa: Tracking 13C Incorporation at Bloom pH Conditions
- Author
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Lauren E. Krausfeldt, Abigail T. Farmer, Hector F. Castro Gonzalez, Brittany N. Zepernick, Shawn R. Campagna, and Steven W. Wilhelm
- Subjects
HABs ,cyanobacteria ,Lake Erie ,nitrogen ,stable isotope probing ,Microbiology ,QR1-502 - Abstract
The use of urea as a nitrogenous fertilizer has increased over the past two decades, with urea itself being readily detected at high concentrations in many lakes. Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen (N) - source for cyanobacteria that possess the enzyme urease. We tested the hypothesis that urea may also act as a carbon (C) source to supplemental growth requirements during the alkaline conditions created by dense cyanobacterial blooms, when concentrations of dissolved CO2 are vanishingly low. High rates of photosynthesis markedly reduce dissolved CO2 concentrations and drive up pH. This was observed in Lake Erie during the largest bloom on record (2015) over long periods (months) and short periods (days) of time, suggesting blooms experience periods of CO2-limitation on a seasonal and daily basis. We used 13C-urea to demonstrate that axenic cultures of the model toxic cyanobacterium, Microcystis aeruginosa NIES843, assimilated C at varying environmentally relevant pH conditions directly into a spectrum of metabolic pools during urea hydrolysis. Primarily, 13C from urea was assimilated into central C metabolism and amino acid biosynthesis pathways, including those important for the production of the hepatotoxin, microcystin, and incorporation into these pathways was at a higher percentage during growth at higher pH. This corresponded to increased growth rates on urea as the sole N source with increasing pH. We propose this ability to incorporate C from urea represents yet another competitive advantage for this cyanobacterium during dense algal blooms.
- Published
- 2019
- Full Text
- View/download PDF
3. Elucidating Duramycin’s Bacterial Selectivity and Mode of Action on the Bacterial Cell Envelope
- Author
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Sahar Hasim, David P. Allison, Berlin Mendez, Abigail T. Farmer, Dale A. Pelletier, Scott T. Retterer, Shawn R. Campagna, Todd B. Reynolds, and Mitchel J. Doktycz
- Subjects
duramycin ,lipid ,phosphatidylethanolamine (PE) ,peptidoglycan ,atomic force microscopy (AFM) ,lipidomics ,Microbiology ,QR1-502 - Abstract
The use of naturally occurring antimicrobial peptides provides a promising route to selectively target pathogenic agents and to shape microbiome structure. Lantibiotics, such as duramycin, are one class of bacterially produced peptidic natural products that can selectively inhibit the growth of other bacteria. However, despite longstanding characterization efforts, the microbial selectivity and mode of action of duramycin are still obscure. We describe here a suite of biological, chemical, and physical characterizations that shed new light on the selective and mechanistic aspects of duramycin activity. Bacterial screening assays have been performed using duramycin and Populus-derived bacterial isolates to determine species selectivity. Lipidomic profiles of selected resistant and sensitive strains show that the sensitivity of Gram-positive bacteria depends on the presence of phosphatidylethanolamine (PE) in the cell membrane. Further the surface and interface morphology were studied by high resolution atomic force microscopy and showed a progression of cellular changes in the cell envelope after treatment with duramycin for the susceptible bacterial strains. Together, these molecular and cellular level analyses provide insight into duramycin’s mode of action and a better understanding of its selectivity.
- Published
- 2018
- Full Text
- View/download PDF
4. Nitrogen flux into metabolites and microcystins changes in response to different nitrogen sources in <scp> Microcystis aeruginosa NIES </scp> ‐843
- Author
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Lauren E. Krausfeldt, Gregory L. Boyer, Steven W. Wilhelm, Abigail T. Farmer, Shawn R. Campagna, and Hector F. Castro
- Subjects
Microcystis ,Microcystins ,Nitrogen ,chemistry.chemical_element ,Microcystin ,Microbiology ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Nitrate ,Ammonium Compounds ,polycyclic compounds ,Urea ,Ammonium ,Microcystis aeruginosa ,Biomass ,Amino Acids ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,chemistry.chemical_classification ,0303 health sciences ,biology ,030306 microbiology ,Hepatotoxin ,biology.organism_classification ,chemistry ,Environmental chemistry - Abstract
The over-enrichment of nitrogen (N) in the environment has contributed to severe and recurring harmful cyanobacterial blooms, especially by the non-N(2)-fixing Microcystis spp. N chemical speciation influences cyanobacterial growth, persistence and the production of the hepatotoxin microcystin, but the physiological mechanisms to explain these observations remain unresolved. Stable-labelled isotopes and metabolomics were employed to address the influence of nitrate, ammonium, and urea on cellular physiology and production of microcystins in Microcystis aeruginosa NIES-843. Global metabolic changes were driven by both N speciation and diel cycling. Tracing (15)N-labelled nitrate, ammonium, and urea through the metabolome revealed N uptake, regardless of species, was linked to C assimilation. The production of amino acids, like arginine, and other N-rich compounds corresponded with greater turnover of microcystins in cells grown on urea compared to nitrate and ammonium. However, (15)N was incorporated into microcystins from all N sources. The differences in N flux were attributed to the energetic efficiency of growth on each N source. While N in general plays an important role in sustaining biomass, these data show that N-speciation induces physiological changes that culminate in differences in global metabolism, cellular microcystin quotas and congener composition.
- Published
- 2020
5. Loss of carotenoids from membranes of Pantoea sp. YR343 results in altered lipid composition and changes in membrane biophysical properties
- Author
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Sushmitha Vijaya Kumar, Amber N. Bible, Graham Taylor, Abigail T. Farmer, Shawn R. Campagna, Mitchel J. Doktycz, Jennifer L. Morrell-Falvey, C. Patrick Collier, and Sahar Hasim
- Subjects
Membrane Fluidity ,Biophysics ,Fluorescence Polarization ,Biochemistry ,Biophysical Phenomena ,Cell wall ,03 medical and health sciences ,Membrane fluidity ,Secretion ,030304 developmental biology ,0303 health sciences ,biology ,Pantoea ,030306 microbiology ,Chemistry ,Vesicle ,Cell Membrane ,Fatty Acids ,Wild type ,Cell Biology ,Lipid Metabolism ,biology.organism_classification ,Carotenoids ,Membrane ,Membrane protein - Abstract
Bacterial membranes are complex mixtures of lipids and proteins, the combination of which confers biophysical properties that allows cells to respond to environmental conditions. Carotenoids are sterol analogs that are important for regulating membrane dynamics. The membrane of Pantoea sp. YR343 is characterized by the presence of the carotenoid zeaxanthin, and a carotenoid-deficient mutant, ΔcrtB, displays defects in root colonization, reduced secretion of indole-3-acetic acid, and defects in biofilm formation. Here we demonstrate that the loss of carotenoids results in changes to the membrane lipid composition in Pantoea sp. YR343, including increased amounts of unsaturated fatty acids in the ΔcrtB mutant membranes. These mutant cells displayed less fluid membranes in comparison to wild type cells as measured by fluorescence anisotropy of whole cells. Studies with artificial systems, however, have shown that carotenoids impart membrane rigidifying properties. Thus, we examined membrane fluidity using spheroplasts and vesicles composed of lipids extracted from either wild type or mutant cells. Interestingly, with the removal of the cell wall and membrane proteins, ΔcrtB vesicles were more fluid than vesicles made from lipids extracted from wild type cells. In addition, carotenoids appeared to stabilize membrane fluidity during rapidly changing temperatures. Taken together, these results suggest that Pantoea sp. YR343 compensates for the loss of carotenoids by changing lipid composition, which together with membrane proteins, results in reduced membrane fluidity. These changes may influence the abundance or function of membrane proteins that are responsible for the physiological changes observed in the ΔcrtB mutant cells.
- Published
- 2019
6. Feeding increasing amounts of ruminally protected choline decreased fatty liver in nonlactating, pregnant Holstein cows in negative energy status
- Author
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José E. P. Santos, M.B. Poindexter, C.R. Staples, J.E. Zuniga, Bruce A. Barton, Tracy L. Scheffler, M.G. Zenobi, Abigail T. Farmer, Shawn R. Campagna, and H.F. Castro Gonzalez
- Subjects
0301 basic medicine ,Cattle Diseases ,Ice calving ,Choline ,03 medical and health sciences ,chemistry.chemical_compound ,Animal science ,Blood plasma ,Genetics ,medicine ,Animals ,Dry matter ,Lipotropic ,Glycogen ,Cholesterol ,Fatty liver ,0402 animal and dairy science ,04 agricultural and veterinary sciences ,medicine.disease ,040201 dairy & animal science ,Diet ,Fatty Liver ,030104 developmental biology ,Liver ,chemistry ,Cattle ,Female ,Animal Science and Zoology ,Food Science - Abstract
The objectives were to determine the optimal feeding amount of choline in a ruminally protected form to reduce the triacylglycerol (TAG) concentration in liver and to increase TAG in blood plasma of dairy cows. Pregnant, nonlactating multiparous Holstein cows (n = 77) were blocked by body condition score (3.59 ± 0.33) and assigned to treatment at 64 ± 10 d before calculated calving date. Dietary treatments were top-dressing of 0, 30, 60, 90, or 120 g/d of ruminally protected choline (RPC; Balchem Corp., New Hampton, NY) ions to supply the equivalent of 0, 6.5, 12.9, 19.4, and 25.8 g/d of choline ions. Diets were formulated to exceed nutrient requirements for maintenance and pregnancy and fed in ad libitum amounts for the first 5 d. From d 6 to 15, cows were restricted to consume approximately 31% of their net energy requirements to simulate early lactating cows in negative energy balance. Methionine intake was maintained throughout each 15-d period. Liver was biopsied at 5 and 14 d and analyzed for TAG and glycogen. Blood was sampled on d 5 and 14 and plasma analyzed for glucose, insulin, cholesterol, β-hydroxybutyrate, long-chain fatty acids, and haptoglobin. On d 14, a mixture of saturated long-chain fatty acids, ground corn, and dried molasses (50:37:13) was offered (908 g, as-is basis) 10 h after the single daily feeding. Blood samples were collected for 19 h and plasma analyzed for TAG and cholesterol to assess apparent absorption of dietary fat. Mean dry matter intake and energy balance decreased from means of 9.5 to 3.3 kg/d and from 0.6 to −9.2 Mcal of net energy for lactation/d during the ad libitum and restricted feeding periods, respectively. Plasma concentrations of the lipid-soluble choline biomolecules, namely total phosphatidylcholines, total lysophosphatidylcholines, and sphingomyelin, increased with choline supplementation. Feed restriction increased plasma concentrations of β-hydroxybutyrate and free long-chain fatty acids, whereas those of glucose, insulin, and total cholesterol decreased. During feed restriction, concentration of hepatic TAG and plasma haptoglobin decreased linearly, whereas concentration of hepatic glycogen tended to increase quadratically with increasing intake of RPC. After fat supplementation, mean plasma concentration of TAG increased by an average of 21% with intake of RPC ions, peaking at intakes of ≥6.5 g/d of RPC ion. In summary, feeding RPC ions to cows in negative energy balance had increasing lipotropic effects on the liver when consumed up to 25.8 g/d, whereas feeding only 6.5 g/d increased concentrations of hepatic glycogen and TAG in the blood.
- Published
- 2018
7. Purinyl-cobamide is a native prosthetic group of reductive dehalogenases
- Author
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Po Hsiang Wang, Burcu Şimşir, Yongchao Yin, Elizabeth A. Edwards, Abigail T. Farmer, Yi Yang, Shawn R. Campagna, Olivia Molenda, Nannan Jiang, Andrew T. Quaile, Allen K. Bourdon, Jun Yan, Frank E. Löffler, and Meng Bi
- Subjects
0301 basic medicine ,Purine ,Protein Conformation ,030106 microbiology ,Desulfitobacterium ,Article ,Cofactor ,03 medical and health sciences ,chemistry.chemical_compound ,Protein structure ,Biosynthesis ,Molecular Biology ,chemistry.chemical_classification ,biology ,Desulfitobacterium hafniense ,Cell Biology ,biology.organism_classification ,Tetrapyrrole ,Biosynthetic Pathways ,Trichloroethylene ,Metabolic pathway ,030104 developmental biology ,Enzyme ,chemistry ,Biochemistry ,Purines ,biology.protein ,Cobamides ,Oxidoreductases - Abstract
Cobamides such as vitamin B12 are structurally conserved, cobalt-containing tetrapyrrole biomolecules that have essential biochemical functions in all domains of life. In organohalide respiration, a vital biological process for the global cycling of natural and anthropogenic organohalogens, cobamides are the requisite prosthetic groups for carbon-halogen bond-cleaving reductive dehalogenases. This study reports the biosynthesis of a new cobamide with unsubstituted purine as the lower base and assigns unsubstituted purine a biological function by demonstrating that Coα-purinyl-cobamide (purinyl-Cba) is the native prosthetic group in catalytically active tetrachloroethene reductive dehalogenases of Desulfitobacterium hafniense. Cobamides featuring different lower bases are not functionally equivalent, and purinyl-Cba elicits different physiological responses in corrinoid-auxotrophic, organohalide-respiring bacteria. Given that cobamide-dependent enzymes catalyze key steps in essential metabolic pathways, the discovery of a novel cobamide structure and the realization that lower bases can effectively modulate enzyme activities generate opportunities to manipulate functionalities of microbiomes.
- Published
- 2017
8. Urea Is Both a Carbon and Nitrogen Source for Microcystis aeruginosa: Tracking 13C Incorporation at Bloom pH Conditions
- Author
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Brittany N. Zepernick, Steven W. Wilhelm, Lauren E. Krausfeldt, Hector F. Castro Gonzalez, Abigail T. Farmer, and Shawn R. Campagna
- Subjects
Cyanobacteria ,HABs ,Microbiology (medical) ,Urease ,lcsh:QR1-502 ,Microcystin ,Photosynthesis ,Algal bloom ,cyanobacteria ,Microbiology ,nitrogen ,lcsh:Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,Microcystis aeruginosa ,stable isotope probing ,030304 developmental biology ,Lake Erie ,chemistry.chemical_classification ,0303 health sciences ,biology ,030306 microbiology ,Ammonia volatilization from urea ,biology.organism_classification ,chemistry ,13. Climate action ,Environmental chemistry ,biology.protein ,Urea - Abstract
The use of urea as a nitrogenous fertilizer has increased over the past two decades, with urea itself being readily detected at high concentrations in many lakes. Urea has been linked to cyanobacterial blooms as it is a readily assimilated nitrogen (N) - source for cyanobacteria that possess the enzyme urease. We tested the hypothesis that urea may also act as a carbon (C) source to supplemental growth requirements during the alkaline conditions created by dense cyanobacterial blooms, when concentrations of dissolved CO2 are vanishingly low. High rates of photosynthesis markedly reduce dissolved CO2 concentrations and drive up pH. This was observed in Lake Erie during the largest bloom on record (2015) over long periods (months) and short periods (days) of time, suggesting blooms experience periods of CO2-limitation on a seasonal and daily basis. We used 13C-urea to demonstrate that axenic cultures of the model toxic cyanobacterium, Microcystis aeruginosa NIES843, assimilated C at varying environmentally relevant pH conditions directly into a spectrum of metabolic pools during urea hydrolysis. Primarily, 13C from urea was assimilated into central C metabolism and amino acid biosynthesis pathways, including those important for the production of the hepatotoxin, microcystin, and incorporation into these pathways was at a higher percentage during growth at higher pH. This corresponded to increased growth rates on urea as the sole N source with increasing pH. We propose this ability to incorporate C from urea represents yet another competitive advantage for this cyanobacterium during dense algal blooms.
- Published
- 2019
- Full Text
- View/download PDF
9. Expanding lipidomics coverage: effective ultra performance liquid chromatography-high resolution mass spectrometer methods for detection and quantitation of cardiolipin, phosphatidylglycerol, and lysyl-phosphatidylglycerol
- Author
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Brittni M. Woodall, Eric D. Tague, John Robert Harp, Elizabeth M. Fozo, Abigail T. Farmer, and Shawn R. Campagna
- Subjects
Cardiolipins ,Endocrinology, Diabetes and Metabolism ,Clinical Biochemistry ,Phospholipid ,Fatty Acids, Nonesterified ,Orbitrap ,01 natural sciences ,Biochemistry ,Article ,law.invention ,03 medical and health sciences ,chemistry.chemical_compound ,Tandem Mass Spectrometry ,law ,Lipidomics ,Enterococcus faecalis ,Cardiolipin ,Metabolomics ,Chromatography, High Pressure Liquid ,Phospholipids ,030304 developmental biology ,Phosphatidylglycerol ,0303 health sciences ,Chromatography ,Lysine ,Hydrophilic interaction chromatography ,010401 analytical chemistry ,Phosphatidylglycerols ,Biological membrane ,0104 chemical sciences ,chemistry ,lipids (amino acids, peptides, and proteins) - Abstract
INTRODUCTION: Lipidomics can reveal global alterations in a broad class of molecules whose functions are innately linked to physiology. Monitoring changes in the phospholipid composition of biological membranes in response to stressors can aid the development of targeted therapies. However, exact quantitation of cardiolipins is not a straightforward task due to low ionization efficiencies and poor chromatographic separation of these compounds. OBJECTIVE: The aim of this study was to develop a quantitative method for the detection of cardiolipins and other phospholipids using both a targeted and untargeted analyses with a Q-Exactive. METHODS: HILIC chromatography and high-resolution mass spectrometry with parallel reaction monitoring was used to measure changes in lipid concentration. Internal standards and fragmentation techniques allowed for the reliable quantitation of lipid species including: lysyl-phosphatidylglycerol, phosphatidylglycerol, and cardiolipin. RESULTS: The untargeted analysis was capable to detecting 6 different phospholipid classes as well as free fatty acids. The targeted analysis quantified up to 23 cardiolipins, 10 phosphatidylglycerols and 10 lysyl-phosphatidylglycerols with detection limits as low as 50 nM. Biological validation with Enterococcus faecalis demonstrates sensitivity in monitoring the incorporation of exogenously supplied free fats into membrane phospholipids. When supplemented with oleic acid, the amount of free oleic acid in the membrane was 100 times greater and the concentration of polyunsaturated cardiolipin increased to over 3.5 μM compared to controls. CONCLUSIONS: This lipidomics method is capable of targeted quantitation for challenging biologically relevant cardiolipins as well as broad, untargeted lipid profiling.
- Published
- 2019
10. Bifunctional amyloid-reactive peptide promotes binding of antibody 11-1F4 to diverse amyloid types and enhances therapeutic efficacy
- Author
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Eric D. Tague, Abigail T. Farmer, Shawn R. Campagna, Emily B. Martin, Craig Wooliver, R. Eric Heidel, James S. Foster, Ronald H. Lands, Jonathan S. Wall, Alan Stuckey, Angela Williams, Stephen J. Kennel, Sallie Macy, and Tina Richey
- Subjects
0301 basic medicine ,Amyloid ,Amyloidogenic Proteins ,Peptide ,Epitope ,Epitopes ,Mice ,03 medical and health sciences ,Positron Emission Tomography Computed Tomography ,Spect imaging ,Antibodies, Bispecific ,mental disorders ,Cadaver ,Amyloid precursor protein ,AL amyloidosis ,medicine ,Animals ,Humans ,Tissue Distribution ,Serum amyloid A ,chemistry.chemical_classification ,Serum Amyloid A Protein ,Multidisciplinary ,biology ,Chemistry ,Amyloidosis ,Antibodies, Monoclonal ,medicine.disease ,Treatment Outcome ,030104 developmental biology ,PNAS Plus ,biology.protein ,Cancer research ,Immunoglobulin Light Chains ,Peptides ,Protein Binding - Abstract
Amyloidosis is a malignant pathology associated with the formation of proteinaceous amyloid fibrils that deposit in organs and tissues, leading to dysfunction and severe morbidity. More than 25 proteins have been identified as components of amyloid, but the most common form of systemic amyloidosis is associated with the deposition of amyloid composed of Ig light chains (AL). Clinical management of amyloidosis focuses on reducing synthesis of the amyloid precursor protein. However, recently, passive immunotherapy using amyloid fibril-reactive antibodies, such as 11-1F4, to remove amyloid from organs has been shown to be effective at restoring organ function in patients with AL amyloidosis. However, 11-1F4 does not bind amyloid in all AL patients, as evidenced by PET/CT imaging, nor does it efficiently bind the many other forms of amyloid. To enhance the reactivity and expand the utility of the 11-1F4 mAb as an amyloid immunotherapeutic, we have developed a pretargeting "peptope" comprising a multiamyloid-reactive peptide, p5+14, fused to a high-affinity peptide epitope recognized by 11-1F4. The peptope, known as p66, bound the 11-1F4 mAb in vitro with subnanomolar efficiency, exhibited multiamyloid reactivity in vitro and, using tissue biodistribution and SPECT imaging, colocalized with amyloid deposits in a mouse model of systemic serum amyloid A amyloidosis. Pretreatment with the peptope induced 11-1F4 mAb accumulation in serum amyloid A deposits in vivo and enhanced 11-1F4-mediated dissolution of a human AL amyloid extract implanted in mice.
- Published
- 2018
11. The corrinoid cofactor of reductive dehalogenases affects dechlorination rates and extents in organohalide-respiring Dehalococcoides mccartyi
- Author
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Abigail T. Farmer, Shawn R. Campagna, Yi Yang, Meng Bi, Jun Yan, Frank E. Löffler, and Burcu Şimşir
- Subjects
0301 basic medicine ,Halogenation ,Auxotrophy ,030106 microbiology ,Vinyl Chloride ,Microbiology ,Vinyl chloride ,Cofactor ,03 medical and health sciences ,chemistry.chemical_compound ,Corrinoid ,Reductive dechlorination ,Ecology, Evolution, Behavior and Systematics ,Dehalogenase ,biology ,Strain (chemistry) ,Chloroflexi ,Ethylenes ,biology.organism_classification ,Dichloroethylenes ,Biodegradation, Environmental ,chemistry ,Biochemistry ,biology.protein ,Benzimidazoles ,Original Article ,Cobamides ,Water Pollutants, Chemical ,Bacteria - Abstract
Corrinoid auxotrophic organohalide-respiring Dehalococcoides mccartyi (Dhc) strains are keystone bacteria for reductive dechlorination of toxic and carcinogenic chloroorganic contaminants. We demonstrate that the lower base attached to the essential corrinoid cofactor of reductive dehalogenase (RDase) enzyme systems modulates dechlorination activity and affects the vinyl chloride (VC) RDases BvcA and VcrA differently. Amendment of 5,6-dimethylbenzimidazolyl-cobamide (DMB-Cba) to Dhc strain BAV1 and strain GT cultures supported cis-1,2-dichloroethene-to-ethene reductive dechlorination at rates of 107.0 (±12.0) μM and 67.4 (±1.4) μM Cl(-) released per day, respectively. Strain BAV1, expressing the BvcA RDase, reductively dechlorinated VC to ethene, although at up to fivefold lower rates in cultures amended with cobamides carrying 5-methylbenzimidazole (5-MeBza), 5-methoxybenzimidazole (5-OMeBza) or benzimidazole (Bza) as the lower base. In contrast, strain GT harboring the VcrA RDase failed to grow and dechlorinate VC to ethene in medium amended with 5-OMeBza-Cba or Bza-Cba. The amendment with DMB to inactive strain GT cultures restored the VC-to-ethene-dechlorinating phenotype and intracellular DMB-Cba was produced, demonstrating cobamide uptake and remodeling. The distinct responses of Dhc strains with BvcA versus VcrA RDases to different cobamides implicate that the lower base exerts control over Dhc reductive dechlorination rates and extents (that is, detoxification), and therefore the dynamics of Dhc strains with discrete reductive dechlorination capabilities. These findings emphasize that the role of the corrinoid/lower base synthesizing community must be understood to predict strain-specific Dhc activity and achieve efficacious contaminated site cleanup.
- Published
- 2015
12. Author Correction: Maternal consumption of fish oil programs reduced adiposity in broiler chicks
- Author
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Sarah Howard, Robert L. Hettich, Suchita Das, Brynn H. Voy, Ronique C. Beckford, Jeanna L. Wilson, Abigail T. Farmer, Shawn R. Campagna, and Jiali Yu
- Subjects
Male ,Maternal consumption ,Multidisciplinary ,lcsh:R ,Broiler ,lcsh:Medicine ,Biology ,Fish oil ,PPAR gamma ,Lipoprotein Lipase ,Fish Oils ,Animal science ,Adipose Tissue ,ComputingMethodologies_DOCUMENTANDTEXTPROCESSING ,Animals ,Female ,lcsh:Q ,Author Correction ,lcsh:Science ,Chickens ,Cytoskeleton ,Adiposity - Abstract
Maternal intake of eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (22:6 n-3) has been associated with reduced adiposity in children, suggesting the possibility to program adipose development through dietary fatty acids before birth. This study determined if enriching the maternal diet in fish oil, the primary source of EPA and DHA, affected adipose development in offspring. Broiler chickens were used because they are obesity-prone, and because fatty acids provided to the embryo can be manipulated through the hen diet. Hens were fed diets supplemented (2.8% wt:wt) with corn oil (CO; n-6) or fish oil (FO; n-3) for 28 d. Chicks from both maternal diet groups were fed the same diet after hatch. Maternal FO consumption enriched chick adipose tissue in EPA and DHA and reduced adiposity by promoting more, but smaller, adipocytes. This adipocyte profile was paralleled by upregulated expression of the adipogenic regulator PPARG and its co-activator PPARGC1B, and reduced expression of LPL. Proteomics identified 95 differentially abundant proteins between FO and CO adipose tissue, including components of glucose metabolism, lipid droplet trafficking, and cytoskeletal organization. These results demonstrate that the maternal dietary fatty acid profile programs offspring adipose development.
- Published
- 2018
13. Understanding Electrochemically Activated Persulfate and Its Application to Ciprofloxacin Abatement
- Author
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Laura W. Matzek, Andrew D. Steen, Abigail T. Farmer, Matthew Tipton, and Kimberly E. Carter
- Subjects
02 engineering and technology ,General Chemistry ,Electrolyte ,010501 environmental sciences ,021001 nanoscience & nanotechnology ,Electrochemistry ,Persulfate ,01 natural sciences ,Anode ,chemistry.chemical_compound ,Wastewater ,chemistry ,Nitrate ,Ciprofloxacin ,Environmental Chemistry ,Degradation (geology) ,Sulfate ,Diamond ,0210 nano-technology ,Electrodes ,Oxidation-Reduction ,Water Pollutants, Chemical ,0105 earth and related environmental sciences ,Nuclear chemistry ,Boron - Abstract
This study offers insight into the roles anodic and cathodic processes play in electrochemically activated persulfate (EAP) and screens EAP as a viable technique for ciprofloxacin degradation in wastewater. Sulfate radical formation at a boron-doped diamond (BDD) anode and persulfate activation at a graphite cathode were experimentally elucidated using different electrolytes and electrochemical setups. Rapid ciprofloxacin transformation occurred via pseudo-first-order mechanisms with respect to ciprofloxacin in persulfate electrolyte, reaching 84% removal in 120 min using EAP. Transformation pathways were compared to those in nitrate and sulfate electrolytes. Ciprofloxacin removal rates in the electrochemical system were 88% and 33% faster in persulfate than nitrate and sulfate electrolytes, respectively. Total organic carbon removal rates were 93% and 48% faster in persulfate than nitrate and sulfate, respectively. Use of sulfate electrolyte resulted in removal rates 6-7 times faster than those in nitrate solution. Accelerated removal in sulfate was attributed to anodic sulfate radical formation, while enhanced removal in persulfate was associated with cathodic persulfate activation and nonradical persulfate activation at the BDD anode. Quenching experiments indicated both sulfate radicals and hydroxyl radicals contributed to degradation. Comparisons between platinum and graphite cathodes showed similar cathodic persulfate activation and ciprofloxacin degradation.
- Published
- 2018
14. Maternal consumption of fish oil programs reduced adiposity in broiler chicks
- Author
-
Sarah Howard, Brynn H. Voy, Ronique C. Beckford, Robert L. Hettich, Jiali Yu, Suchita Das, Abigail T. Farmer, Shawn R. Campagna, and Jeanna L. Wilson
- Subjects
0301 basic medicine ,medicine.medical_specialty ,Multidisciplinary ,Offspring ,lcsh:R ,Adipose tissue ,lcsh:Medicine ,Biology ,Carbohydrate metabolism ,Fish oil ,Eicosapentaenoic acid ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Endocrinology ,chemistry ,Docosahexaenoic acid ,Internal medicine ,Adipocyte ,medicine ,lcsh:Q ,lcsh:Science ,Corn oil - Abstract
Maternal intake of eicosapentaenoic acid (EPA; 20:5 n-3) and docosahexaenoic acid (22:6 n-3) has been associated with reduced adiposity in children, suggesting the possibility to program adipose development through dietary fatty acids before birth. This study determined if enriching the maternal diet in fish oil, the primary source of EPA and DHA, affected adipose development in offspring. Broiler chickens were used because they are obesity-prone, and because fatty acids provided to the embryo can be manipulated through the hen diet. Hens were fed diets supplemented (2.8% wt:wt) with corn oil (CO; n-6) or fish oil (FO; n-3) for 28 d. Chicks from both maternal diet groups were fed the same diet after hatch. Maternal FO consumption enriched chick adipose tissue in EPA and DHA and reduced adiposity by promoting more, but smaller, adipocytes. This adipocyte profile was paralleled by lower expression of the adipogenic regulator PPARG and its co-activator PPARGC1B, and elevated expression of LPL. Proteomics identified 95 differentially abundant proteins between FO and CO adipose tissue, including components of glucose metabolism, lipid droplet trafficking, and cytoskeletal organization. These results demonstrate that the maternal dietary fatty acid profile programs offspring adipose development.
- Published
- 2017
15. Role of phosphatidylserine synthase in shaping the phospholipidome of Candida albicans
- Author
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Terry K. Smith, Anthony E. Montedonico, Todd B. Reynolds, Abigail T. Farmer, Shawn R. Campagna, Chelsi D. Cassilly, University of St Andrews. School of Biology, and University of St Andrews. Biomedical Sciences Research Complex
- Subjects
0301 basic medicine ,QH301 Biology ,030106 microbiology ,NDAS ,Virulence ,CDPdiacylglycerol-Serine O-Phosphatidyltransferase ,Applied Microbiology and Biotechnology ,Microbiology ,Substrate Specificity ,QH301 ,03 medical and health sciences ,chemistry.chemical_compound ,Candida albicans ,QD ,Phosphatidylinositol ,Phosphatidylserine ,Phospholipids ,chemistry.chemical_classification ,Phosphatidylethanolamine ,biology ,ATP synthase ,Phosphatidylglycerol ,QR Microbiology ,General Medicine ,Phosphatidic acid ,QD Chemistry ,biology.organism_classification ,QR ,Phosphatidylcholine ,Kinetics ,030104 developmental biology ,Enzyme ,Biochemistry ,chemistry ,Lipidomics ,biology.protein ,Gene Deletion ,Research Article - Abstract
This work was supported by the National Institutes of Health NIH R01AL105690. Phosphatidylserine (PS) synthase (Cho1p) and the PS decarboxylase enzymes (Psd1p and Psd2p), which synthesize PS and phosphatidylethanolamine (PE), respectively, are crucial for Candida albicans virulence. Mutations that disrupt these enzymes compromise virulence. These enzymes are part of the cytidine diphosphate-diacylglycerol pathway (i.e. de novo pathway) for phospholipid synthesis. Understanding how losses of PS and/or PE synthesis pathways affect the phospholipidome of Candida is important for fully understanding how these enzymes impact virulence. The cho1Δ/Δ and psd1Δ/Δ psd2Δ/Δ mutations cause similar changes in levels of phosphatidic acid, phosphatidylglycerol, phosphatidylinositol and PS. However, only slight changes were seen in PE and phosphatidylcholine (PC). This finding suggests that the alternative mechanism for making PE and PC, the Kennedy pathway, can compensate for loss of the de novo synthesis pathway. Candida albicans Cho1p, the lipid biosynthetic enzyme with the most potential as a drug target, has been biochemically characterized, and analysis of its substrate specificity and kinetics reveal that these are similar to those previously published for Saccharomyces cerevisiae Cho1p. Postprint
- Published
- 2017
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