Trainee Mini-grant Awardees

The Training Core awards a number of mini-grants each year to our trainees for research projects. Below are summaries of the grants awarded since 2019, beginning with the most recent.

Paige Varner

Sequencing the genome of Pseudomonas putida G7 harboring the naphthalene-degrading plasmid NAH7 for the purpose of promoting bioremediation of PAHs – September 2020

Paige Varner (PhD student, Gunsch lab) aims to sequence the genome of Pseudomonas putida G7 (G7) which harbors the naphthalene-degrading plasmid NAH7. Because this plasmid is well-characterized, it has been widely used to study bioremediation of polycyclic aromatic hydrocarbons (PAHs). Particularly this plasmid is an ideal candidate for genetic bioaugmentation (inserting relvant genes into the environment) because it is self-transmissible and well-characterized. This will allow for a deeper understanding of plasmid transfer for the purpose of bioremediation of PAHs. This knowledge will advance the goals of Project 5 by maximizing the PAH degradation in sediments. Additionally, this project will allow collaboration between Project 5 of the Duke SRP and the Duke Center for Genomic and Computational Biology.

Axel Berky

Toxic Trace Metals and their Health Implications on Public Health in Madre de Dios, Peru – February 2020

Axel Berky (PhD student, Pan lab) will assess the health effects of mixed trace metal exposures in a Peruvian population where other co-exposures are limited. This allows for a more robust assessment relating toxic trace metals to health outcomes. The specific aims are: 1) evaluate mixed metal exposures in Madre de Dios, Peru where mercury exposure has already been demonstrated to be highly pervasive; 2) utilize cross-sectional exposure, along with in-depth survey and detailed health data to quantify the effect of mixed metal exposure on cardiovascular and kidney health and 3) implement different statistical methods to identify a model that most accurately fits mixed exposures. This will allow us to more accurately assess mixed exposures and begin to link exposures to health outcomes, while adjusting for important covariates.

Daniel Raudabaugh

Direct and Indirect Effects of Polycyclic Aromatic Hydrocarbons on Host-fungal partnerships and their potnetial to be leveraged for bio-remediation – February 2020

The importance of fungi as key drivers of aquatic ecosystem functions and their symbiotic relationships to host plants has been extensively researched. Plants have been known to uptake legacy and emerging pollutants, including polycyclic aromatic hydrocarbons (PAHs), via root uptake and subsequent translocation and through their stomata via atmospheric deposition. Unfortunately no research has been conducted to understand how these pollutants affect root-associated and endophytic fungi. To address this deficiency Daniel Raudabaugh (Postdoc, Gunsch lab) will: 1) root-associated and endophytic fungi will be isolated from Phragmites australis (common reed) and Spartina alterniflora (salt marsh cordgrass) roots, and 2) culture-independent analyses will be completed to elucidate changes in fungal root-associated diversity and phylogenetic structure.

Beverly deSouza

Comparing the mutagenic potentials of PAH-containing samples that have been bioaugmented by bacterial strains with PAH-degrading capability – February 2020

Project 5 of the Duke Superfund Research Center aims to develop bioaugmentation strategies that employ bacteria and fungi to degrade environmental PAHs. Bioaugmentation offers the promise of removal of PAHs from contaminated sites without the environmental disruption and cost associated with currently used remediation methods such as dredging and capping. A potential drawback to bioremediation, however, is that microorganisms can create toxic byproducts in the degradation process. Beverly deSouza (Master’s student, Gunsch lab) will compare the mutagenic potentials of PAH-containing samples that have been bioaugmented with 3 bacterial strains isolated from the former Republic Creosoting site in the Elizabeth River, VA, with that of untreated controls.

Kathleen Hershberger

Investigating potential mechanisms of later-life effects of a developmental exposure to arsenic using a multi-omics approach – January 2020

Arsenic is a well-established environmental toxicant that contributes to the pathogenesis of a number of diseases including cardiomyopathy, neuropathy, and cancers. Mitochondria biogenesis and reprogramming occur during early development and may be a period of heightened vulnerability to mitochondrial toxicants, including arsenic. However, understanding the long-term effects of exposure to arsenic during early development is prohibitively difficult to study in long-term epidemiological studies. The Meyer lab (Project 3) exposes C. elegans to arsenic in early development and follow the animals into adulthood. In this project, Kathleen Hershberger (Postdoc, Meyer lab) will determine potential mechanisms of later-life effects of a developmental exposure to arsenic using a multi-omics approach.

Zade Holloway

Neurodevelopmental effects of vitamin E in embryonic zebrafish exposed to benzo[a]pyrene – February 2019

Analysis of effects on organisms and the environment from benzo[a]pyrene (BaP) exposure is a prominent theme in Duke SRP research, and advances in therapeutic treatments would greatly enhance our understanding and progress in this field. To date, vitamin E has not been explored as a therapeutic agent on embryonic development in the presence of this potent neurotoxin. Zade Holloway’s (Postdoc, Levin lab) project will benefit Projects 1, 3, and 4 of the Duke SRP by adding valuable data to what is known about the mechanisms of developmental neurotoxicants and their effects on early life exposure. This work will further our understanding of how antioxidants and other vitamin supplements may help protect organisms exposed to PAHs, and lastly provide us with pilot data that may be highly applicable to cases of exposure in humans.