Patrick Freeze, Ph.D.

Patrick Freeze, Ph.D.

Reno, Nevada, United States
9K followers 500+ connections

About

As the Director of Research and Innovation at Phigenics, I lead cutting-edge initiatives…

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Experience

  • Phigenics Graphic

    Phigenics

    Reno, Nevada, United States

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    Kearney, Nebraska, United States

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    Kearney, Nebraska, United States

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    Othello, Washington, United States

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    Corpus Christi, Texas Area

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    Pullman, WA

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    Pullman, WA

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    Pullman, WA

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    Bangkok Metropolitan Area, Thailand

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    Reno, Nevada Area

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    Reno, Nevada, United States

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    Reno, Nevada Area

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    Reno, Nevada Area

Education

  • Washington State University Graphic

    Washington State University

    Activities and Societies: Graduate Student Association, WSU Fulbright Applicant Advisor, Association of International Agriculture and Rural Development Executive Committee

    U.S. Fulbright Scholar, USDA NIFA Needs Fellow

  • Activities and Societies: Alpha Zeta, Student Association of International Water Issues

    Minor: Analytical Chemistry.
    NASA and NSF EPSCoR Scholarship Recipient
    Focus: Environmental chemistry, metal remediation, forest soil biogeochemistry, EPA policy oversight.

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Publications

  • Phenazine-1-Carboxylic Acid-Producing Bacteria Enhance the Reactivity of Iron Minerals in Dryland and Irrigated Wheat Rhizospheres

    Environmental Science and Technology, ACS Publications

    Phenazine-1-carboxylic acid (PCA) is a broad-spectrum antibiotic produced by rhizobacteria in the dryland wheat fields of the Columbia Plateau. PCA and other phenazines reductively dissolve Fe and Mn oxyhydroxides in bacterial culture systems, but the impact of PCA upon Fe and Mn cycling in the rhizosphere is unknown. Here, concentrations of dithionite-extractable and poorly crystalline Fe were approximately 10% and 30–40% higher, respectively, in dryland and irrigated rhizospheres inoculated…

    Phenazine-1-carboxylic acid (PCA) is a broad-spectrum antibiotic produced by rhizobacteria in the dryland wheat fields of the Columbia Plateau. PCA and other phenazines reductively dissolve Fe and Mn oxyhydroxides in bacterial culture systems, but the impact of PCA upon Fe and Mn cycling in the rhizosphere is unknown. Here, concentrations of dithionite-extractable and poorly crystalline Fe were approximately 10% and 30–40% higher, respectively, in dryland and irrigated rhizospheres inoculated with the PCA-producing (PCA+) strain Pseudomonas synxantha 2–79 than in rhizospheres inoculated with a PCA-deficient mutant. However, rhizosphere concentrations of Fe(II) and Mn did not differ significantly, indicating that PCA-mediated redox transformations of Fe and Mn were transient or were masked by competing processes. Total Fe and Mn uptake into wheat biomass also did not differ significantly, but the PCA+ strain significantly altered Fe translocation into shoots. X-ray absorption near edge spectroscopy revealed an abundance of Fe-bearing oxyhydroxides and phyllosilicates in all rhizospheres. These results indicate that the PCA+ strain enhanced the reactivity and mobility of Fe derived from soil minerals without producing parallel changes in plant Fe uptake. This is the first report that directly links significant alterations of Fe-bearing minerals in the rhizosphere to a single bacterial trait.

    Other authors
    • LeTourneau, M.
    • Marshall, M.
    • Grant, M.
    • Freeze, P.
    • Strawn, D.
    • Lai, B.
    • Dohnalkova, A.
    • Harsh, J.
    • Weller, D.
    • Thomashow, L.
    See publication
  • The Use of Fe-Rich Compost for the Amelioration of As-Contaminated Soils

    Mineralogical Society, Goldschmidt 2013, Presentation Abstract

    Presentation abstract for the Goldschmidt 2013 Geochemical Conference, held in Bologna, Italy.

    Freeze P, Harsh J, Shi Z, Abi-Ghanem R & Okubara P
    Mineralogical Magazine Jul 2013, 77 (5) 1058-1124; DOI: 10.1180/minmag.2013.077.5.6

    Other authors
    See publication
  • Abstract: Biogeochemistry of a soil catena in the eastern Sierra Nevada Range, NV

    68th International Soil and Water Conservation Society International Annual Conference Abstract Book

    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized five pedons at Little Valley, NV, at the eastern edge of the Sierra Nevada. Characterizing and understanding the pedogenesis of this and other catenas could be used as a baseline for assessing the effects of management decisions, fire, and climate-change.

    Other authors
    • Bob Blank
    • Dale Johnson
    • Tye Morgan
    • Rachel Jones
    • Robin Lawrence
    • Anna Lue
    • Lauren Roaldson
    • Jake Steinman
    • Casandra Woodward
    See publication
  • Intermittent Rainstorms Cause Pulses of Nitrogen, Phosphorus, and Copper in Leachate from Compost in Bioretention Systems

    Journal: Science of the Total Environment

    Bioretention systems rely on vegetation and mixtures of soil, sand, and compost to filter stormwater runoff. However, bioretention systems can also leach metals and nutrients, and compost may be a major contributor to this leaching. To safely implement bioretention systems, it is crucial to determine the composition of compost leachate. We characterized and quantified the leachate composition of compost following intermittent, simulated storm events. Columns of municipal compost were irrigated…

    Bioretention systems rely on vegetation and mixtures of soil, sand, and compost to filter stormwater runoff. However, bioretention systems can also leach metals and nutrients, and compost may be a major contributor to this leaching. To safely implement bioretention systems, it is crucial to determine the composition of compost leachate. We characterized and quantified the leachate composition of compost following intermittent, simulated storm events. Columns of municipal compost were irrigated to simulate 6-month, 24-hour rain storms in the Seattle-Tacoma region. Outflow was analyzed for pH, electrical conductivity (EC), particulate concentration, surface tension, dissolved organic carbon (DOC), nitrogen, phosphorus, and copper. Results indicate a decrease of chemical concentrations over the course of individual storms and following repeated storms, but each new storm released another peak of constituents. The decrease in phosphorus, copper, and DOC concentrations with repeated storms was slower than for nitrate and EC. Nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) showed that the DOC consisted mainly of aliphatic and aromatic components typical of fulvic and humic acids. Less than 3% of the original copper content from the compost leached out even after nine storm events. Nonetheless, copper concentrations in the leachate exceeded regulatory discharge standards. Our results show that compost can serve as a sustained source of leaching of nutrients and metals.

    Other authors
    • Jessica Mulane
    • Markus Flury
    • Curtis Hinman
    • Craig Cogger
    • Zhenqing Shi
    • Hamid Iqbal
    See publication

Projects

  • Ph.D. Dissertation: Reducing Arsenic and Lead Mobility and Bioavailability in Contaminated Soil and Stormwater Runoff

    - Present

    Investigation of physico-chemical properties of iron-enhanced biofiltration media, and its capacity to attenuate arsenic in soil and stormwater runoff (kinetics, adsorption and transport modeling)

  • U.S. Fulbright Scholar Award, 2015-2016: Heavy Metals and Plant Uptake: Cadmium Contamination in Rice Paddies (Thailand)

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    Kasetsart University, Bangkok Thailand.

    Investigating the physical and chemical properties of rice husk biochar and its ability to reduce cadmium availability and uptake in rice paddies, Mae Tak, Mae Sot Province, Thailand

    See project
  • Microbial Contribution to Organic Carbon Sequestration in Mineral Soil

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    Emerging Research Issues for Washington Agriculture Grant

    Quantitative investigation into biofilm formation on various media found in soils

    Other creators
  • Biogeochemistry of a soil catena in the eastern Sierra Nevada Range, NV

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    As a field/lab project, students in the Soil Biogeochemistry class of the University of Nevada, Reno described and characterized five pedons at Little Valley, NV, at the eastern edge of the Sierra Nevada.

    See project
  • Ghanaian EPA Policy Workshop: Ghana, Africa

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    "Empowering young environmental leaders in Ghana, the U.S. and Liberia"
    Sponsor: ELAW & Bureau of International Organization Affairs

    Technical Aspects of Tailings, Cyanide Containment, and Environmental Assessments: Comparative Policy and Procedure Study on Mining in Western Ghana

    Focus: Environmental assessment processes, proper mining practices, impacts on rural farmers (Tarkwa)

    See project
  • Field Methods in Ecohydrology: Studies in an Urban Watershed

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    Chemical and biological assessment of impaired waters, 303(d): Alum Creek, Reno NV.

    Site assessment included sample analysis for nitrogen, phosphorus, pH, E.coli, heavy metals, and turbidity, as well as EC, temperature, and creek discharge rates. Data was presented to city managers and the neighboring homeowners association.

    See project

Honors & Awards

  • U.S. Fulbright Scholar Award

    U.S. Fulbright Program

    Academic year: 2015-2016
    Location: Kasetsart University, Bangkok, Thailand

  • Association of International Agriculture and Rural Development (AIARD) Future Leaders Forum Award, Washington D.C.

    AIARD

    AIARD Future Leader Representative, 2014-2015

    http://www.aiard.org/annual-conference-2014.html

  • USDA National Institute of Food and Agriculture (NIFA) Graduate Fellow

    USDA NIFA - Ph.D. WSU

    USDA NIFA Fellow - August 2012-2013
    Ph.D. Graduate Student, Washington State University

    Organized 2-month international research exchange under USDA NIFA Fellowship:
    1) Naples: Solid-state C13 Nuclear Magnetic Resonance training - Alessandro Piccolo and Ricardo Spaccini Group

    2) Bologna: Marco Bittelli Group: Field research: viticulture research, assessing groundwater movement, soil and root respiration studies, biofuels (switchgrass)

    3) Zurich: Rainer Schulin…

    USDA NIFA Fellow - August 2012-2013
    Ph.D. Graduate Student, Washington State University

    Organized 2-month international research exchange under USDA NIFA Fellowship:
    1) Naples: Solid-state C13 Nuclear Magnetic Resonance training - Alessandro Piccolo and Ricardo Spaccini Group

    2) Bologna: Marco Bittelli Group: Field research: viticulture research, assessing groundwater movement, soil and root respiration studies, biofuels (switchgrass)

    3) Zurich: Rainer Schulin Group: Analytical methods for investigating metal contamination in soils.

    4) Presentated at Goldschmidt 2013 - Florence: The Use of Fe-Rich Compost for the Amelioration of As-Contaminated Soils

Organizations

  • U.S. Fulbright Association

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    - Present
  • WSU Graduate and Professional Student Association

    GPSA Senator - Crops and Soils

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  • Association of International Agriculture and Rural Development (AIARD)

    Future Leader Forum Representative, AIARD Executive Committee

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    http://www.aiard.org/future-leaders-forum-2014.html

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