• Advancing the Science of Microbial Symbiosis to Support Invasive Species Management: A Case Study on Phragmites in the Great Lakes

      Kowalski, Kurt P.; Bacon, Charles; Bickford, Wesley; Braun, Heather; Clay, Keith; Leduc-Lapierre, Michele; Lillard, Elizabeth; McCormick, Melissa K.; Nelson, Eric; Torres, Monica; et al. (2015-02-19)
      A growing body of literature supports microbial symbiosis as a foundational principle for the competitive success of invasive plant species.Further exploration of the relationships between invasive species and their associated microbiomes, as well as the interactions with the microbiomes of native species, can lead to key new insights into invasive success and potentially new and effective control approaches. In this manuscript, we review microbial relationships with plants, outline steps necessary to develop invasive species control strategies that are based on those relationships, and use the invasive plant species Phragmites australis (common reed)as an example of how development of microbial-based control strategies can be enhanced using a collective impact approach. The proposed science agenda, developed by the Collaborative for Microbial Symbiosis and Phragmites Management, contains a foundation of sequential steps and mutually-reinforcing tasks to guide the development of microbial-based control strategies for Phragmites and other invasive species. Just as the science of plant-microbial symbiosis can be transferred for use in other invasive species, so too can the model of collective impact be applied to other avenues of research and management.
    • Effect of Dietary Magnesium Manipulation on the Gastrointestinal Microbiome of a Mouse Model of Ulcerative Colitis

      Ortega, Bernardo; Carlson, Christopher; The College at Brockport (2018-12-17)
      Ulcerative colitis (UC) is a disease characterized by inflammation of the GI tract, which disturbs the mucosal lining and hinders magnesium (Mg2+) absorption. Research has shown that increasing the dietary intake of Mg2+ decreases the severity of the colitis symptoms, but there is no data on the effect this has on the microbiota of the GI tract or the blood. We found that, in DSS-treated mice, the amount of bacteria in the colon increases with a decrease in dietary Mg2+, and that the concentration of bacteria in the spleen does not correlate to symptom severity or to colonic bacterial amounts. Mg2+ could be used as a supplement for UC patients, treating both hypomagnesemia and lowering colonic bacteria closer to healthy levels.
    • Geochemistry and Microbiology of Iron-related Well-screen Encrustation and Aquifer Biofouling in Suffolk County, Long Island, New York

      Walter, Donald A.; USGS (1997-01-01)
      Iron-related well-screen encrustation and aquifer biofouling has decreased the specific capacity of several production wells in Suffolk County, N.Y., and has forced the Suffolk County Water Authority to adopt a costly well-reconditioning and replacement program. The specific-capacity declines are the result of the precipitation of iron oxyhydroxides and the growth of iron bacteria on the well screens and in the pore spaces of the surrounding formation. Mineralogic and chemical analyses indicate that the inorganic part of the encrusting material consists primarily of amorphous ferric hydroxide (Fe(OH)3 ); minor components of the material include goethite (FeOOH), hematite (Fe2 O 3 ), and quartz (SiO 2 ). The weight percent of ferric hydroxide in the material ranged from 32.3 to 98.6 percent and averaged 64.3 percent. Equilibrium modeling indicated that during pumping the well waters were supersaturated with respect to goethite, hematite, magnetite, and quartz and were under-saturated with respect to ferric hydroxide. Theoretical Eh values computed for the ferrous/ferric-iron redox couple and the oxygen/water redox couple averaged 390 millivolts and 810 millivolts, respectively, indicating that the waters were in a state of redox disequilibrium. The disequilibrium condition arises from the mixing of ground water with a low dissolved-oxygen concentration with oxygenated ground water during operation of the well. The low pH of the ground water contributes to the disequilibrium condition by slowing the rate of iron oxidation after the introduction of oxygen. Chemical and mineralogical data indicate that most of the encrusting material in the wells was deposited while the wells were shut down, probably in response to the use of treated water of higher pH to keep pump turbines wet while the wells were not in operation; the increased pH of water in the static water column increases the rate of ferrous-iron oxidation and causes the well water to become increasingly saturated with respect to ferric hydroxide. The median half-time of oxidation in samples of untreated ground water (pH 4-5) was 4.19 days, whereas the average half-time of oxidation in treated water (pH 7-8) was 11.9 minutes Equilibrium modeling indicated that treated waters generally were supersaturated with respect to ferric hydroxide, whereas untreated well waters were not. Field and laboratory data indicate that iron bacteria play an important role in the encrustation and biofouling process in Suffolk County. Filamentous iron bacteria were common in the affected wells. The most common species was Gallionella ferruginea, an effective biofouling agent that prefers water with low, but detectable, dissolved-oxygen concentrations and high dissolved-iron concentrations; this species was more common in biofilm samples from the Magothy aquifer than in those from the upper glacial aquifer. Iron bacteria also were found in sediment cores from several locations in the aquifer and in drilling water. Lignite could act as a carbon source for heterotrophic iron bacteria, which could accelerate the formation of iron-bacteria biofilms in wells screened in some parts of the Magothy aquifer. Iron-bacteria biofilms alter the chemistry of well water by removing iron, manganese, and sulfate from solution and by increasing the pH. Sulfur-reducing bacteria and iron-sulfide mineral phases were observed in some samples of encrusting material, indicating that these bacteria could contribute to well-screen encrustation in some geochemical environments.