Publishing Research

Students can publish their research results with their faculty advisors in academic journals. The UF Center for Undergraduate Research maintains the UF Journal of Undergraduate Research, which is is published once a year. It is open to all undergraduates to submit their research papers. Submissions are reviewed by experts in the field of the paper through a double-blind peer review process.

UF Journal of Undergraduate Research

• UF JUR information and submission guidelines
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BEST/Experiential Learning Lab Publications in UF Journal of Undergraduate Research

• Messer, K.E. and Wilkie, A.C. (2021). Earthworm depuration: Analysis of coprophagy and light impacts. UF Journal of Undergraduate Research 23:1-19. https://doi.org/10.32473/ufjur.v23i.128440

  DOI: 

  https://doi.org/10.32473/ufjur.v23i.128440 

  Abstract:

  Earthworms are used as biomarkers to determine the bioavailability of contaminants. As such, their uptake of contaminants has been studied extensively. Protocols have been established to ensure that laboratory-obtained data are valid and comparable. However, the method of removing the organism’s gut content (depuration) before assessing the contaminant in the tissue is not standardized. The aim of this research project was to investigate some parameters for earthworm depuration: light conditions and coprophagy prevention. Eisenia fetida were depurated for 48 hours in two separate studies according to existing guidelines. In one study, under continuous light conditions, two frequencies of egesta removal were employed during depuration to prevent coprophagy and compared to the control (egesta and worms removed after 48 hours). In another study, the subjects and material egested were assessed under conditions of continuous darkness and compared to the control (continuous light). The depuration methods that included egesta removal every 12 and 24 hours resulted in 62% and 9% more egested material per mg of earthworm than the control (egesta removal after 48 hours), respectively. The earthworms depurated in continuous darkness egested 98% more material per mg of earthworm than the control. The results indicate that there was more complete depuration under continuous darkness or when employing a coprophagy prevention method under continuous light. These findings could lead to more efficient depuration methods.

  Keywords:

  Eisenia fetida, depuration, bioaccumulation, gut voidance, gut kinetics, coprophagy

• Bjorndal, L. and Wilkie, A.C. (2020). Drying of algae: Analysis of Oedogonium dehydration kinetics. UF Journal of Undergraduate Research 22:1-16. https://doi.org/10.32473/ufjur.v22i0.121818

  DOI:

  https://doi.org/10.32473/ufjur.v22i0.121818

  Abstract:

  Algae cultivation has multiple potential applications including biofuel production, wastewater treatment, and carbon capture. However, dewatering and dehydration remain a challenge for commercialization.  Research has focused mainly on microalgae, but filamentous algae have recently gained attention due to their larger size and thus relative ease of harvesting. The drying mechanics of filamentous algae has yet to be fully understood and optimized.  This study investigated the drying behavior of the filamentous algae Oedogonium at 50°C, 60°C, and 70°C.  The moisture content of triplicate samples of microalgae and Oedogonium (intact filaments, fractured filaments, and aggregated forms) was measured during drying. Intact Oedogonium filaments were fractured using a food blender. Intact Oedogonium had an average shorter falling-rate phase and higher diffusivity than microalgae at all temperatures, resulting in a 15%, 8.3%, and 11% faster total average drying time at 50°C, 60°C, and 70°C, respectively. Fractured Oedogonium had a shorter falling-rate phase than intact Oedogonium at 50°C and 60°C where its average total drying time was 18% and 9% faster, respectively, but the effect of the fracturing treatment was reduced with increasing temperature and became negligible at 70°C.Thus, Oedogonium appears to dry more effectively than microalgae and fracturing Oedogonium results in faster dehydration at lower temperatures. These findings could help optimize industrial drying and assist in the commercialization of algae cultivation.

  Keywords:

  Oedogonium, microalgae, drying, cell fracturing, algal cultivation, moisture ratio

• Higgins, B. and Wilkie, A.C. (2019). Screening fecal methanogens in five orders of mammals. Journal of Undergraduate Research 21(1), Fall 2019:1-9. https://doi.org/10.32473/ufjur.v21i1.108561

  DOI:

  https://doi.org/10.32473/ufjur.v21i1.108561

  Abstract:

  Animal waste has been studied as a potential fuel source via anaerobic digestion. Feces have also been used to inoculate biodigesters. Biodigesters are a waste treatment solution that use anaerobic digestion to convert organic matter into methane. They utilize microbes to breakdown organic matter into substrates which are then converted into methane as fuel. The final step’s productivity depends on the methanogen content of the biodigester. This study evaluated the feces of captive animals for use as a methanogenic inoculum. The aim was to assess the potential of different feces for methanogen contribution through a literature review and sample analysis via fluorescence microscopy to observe F420 autofluorescence. Coenzyme F420 is a fluorescent coenzyme involved in redox reactions in methanogens and is used in their identification and observation. The samples were from herbivores in the orders Rodentia (rodents), Lagomorpha (rabbits), Perissodactyla (odd-toed ungulates), Artiodactyla (even-toed ungulates), and Diprotodontia (some marsupials). The literature review favored goats and sheep over the other animals in the study. The feces from each animal species tested were observed to have some methanogen presence, but the levels were low and differences were not discernible. Overall, the results of the sample analyses were inconclusive due to the scarcity of methanogens and obscuration due to foliage fragments.

  Keywords:

  Fecal, Methanogens, Coenzyme F420, Anaerobic digestion, Biodigester, Inoculum

• O’Connell, R. and Wilkie, A.C. (2018). Comparing harvest productivity of the filamentous alga Oedogonium with microalgae. Journal of Undergraduate Research 20(1), Fall 2018:1-9. https://doi.org/10.32473/ufjur.v20i1.106221

  DOI:

  https://doi.org/10.32473/ufjur.v20i1.106221

  Abstract:

  As the planet faces depletion of its natural resources, alternative and sustainable energy sources are becoming increasingly sought after. Research on the growth of algae has revealed their potential for carbon capture to reduce greenhouse gas emissions and for conversion into a fuel source for bioenergy applications. Filamentous algae have attracted recent attention as an optimal species due to their ease of harvest and dominance over other species. To determine the most suitable species for future biomass applications, a 1000-L open raceway pond was inoculated with the freshwater filamentous alga, Oedogonium, with the addition of CO₂. An additional two 1000-L raceway ponds with established cultures of microalgae already receiving CO₂ were used as a comparison to the growth of Oedogonium. The pond culture was harvested weekly to determine culture density/growth (mg VSS/L) and harvest productivity (g VSS/m²-day). After 3 weeks, Oedogonium harvest productivity exceeded both microalgal ponds at 13.7 (± 0.3) g VSS/m²-day compared to 9.3 (± 0.6) and 9.5 (± 0.5) g VSS/m²-day for the microalgae. Thus, Oedogonium could serve as a suitable species for biomass production due to its higher productivity rates when compared with microalgal growth.

  Keywords:

  algae, Oedogonium, bioenergy, filamentous, carbon dioxide

• Sanchez, C. and Wilkie, A.C. (2017). Bioenergy production potential from small ruminant manure. Journal of Undergraduate Research 18(3) (Summer 2017):1-4. http://ufdc.ufl.edu/UF00091523/00828

  Link:

  http://ufdc.ufl.edu/UF00091523/00828

  Abstract:

  Goats and sheep are widely reared on small farms in Florida and in developing countries since they require less land and feed than larger livestock, making them easier and less expensive to maintain. Their pellet-form manure can be easily collected and stored as solid material for anaerobic digestion to recover a sustainable, renewable energy source in the form of methane gas. The post-digestion digestate that remains contains nutrients that can also be applied to land as organic fertilizer. The objectives of this study were to characterize goat and sheep manure and determine their ultimate methane yields to assess their viability as substrates for anaerobic digestion. Fresh sheep and goat manure pellets were collected locally and characterized for total solids (TS), volatile solids (VS), pH, conductivity, alkalinity and chemical oxygen demand (COD). Methane index potential batch assays were conducted on the manure slurries at mesophilic temperature (35°C) for 41 days, in triplicate. The ultimate methane yield was higher in the sheep manure (198 L_NCH₄/kgVS) compared to the goat manure (167 L_NCH₄/kgVS) on a VS basis. However, goat manure had higher TS and VS contents, resulting in a higher methane yield from goat (7.1 LCH₄/lb) versus sheep (5.1 LCH₄/lb) manure on a fresh weight basis. The goat manure reached 46% of its theoretical methane yield on a COD basis while sheep manure reached 42%. Both substrates are viable for anaerobic digestion and methane gas generation as an energy source on small farms.

• Brene, A. and Wilkie, A.C. (2014). Essential nutrient additions for algal bioremediation of reverse osmosis treated landfill leachate. Journal of Undergraduate Research 15(3), 4p. http://ufdc.ufl.edu/UF00091523/00704

  Link:

  http://ufdc.ufl.edu/UF00091523/00704

  Abstract:

  Liquid wastes from landfills, termed landfill leachates, must be managed on a daily basis and for many years after a landfill is closed. Reverse osmosis (RO) is an experimental method for landfill leachate treatment. At the Alachua County Southwest Landfill, the process uses a two-stage RO filtration system to reduce ammoniacal nitrogen to groundwater cleanup target levels. Pairing RO with algal bioremediation may eliminate the need for the second RO treatment step. Primary RO treatment removes nutrients essential for algal growth and therefore adding nutrients to primary RO permeate should increase both algal growth rates and bioremediation rates. The alga Scenedesmus sp. was cultured in primary RO treated landfill leachate with elemental additions and compared with a control. A customized nutrient medium containing essential macro and micronutrients was shown to provide increased algal growth and remediation rates. Landfill leachate was tested as a source of micronutrients and shown to provide equivalent growth and remediation as the customized micronutrient solution, suggesting that low concentrations of landfill leachate may be a viable option as a micronutrient supplement to support algal bioremediation of RO treated landfill leachate.

• Neal, J. and Wilkie, A.C. (2014). Anaerobic digester effluent as fertilizer for hydroponically grown tomatoes. Journal of Undergraduate Research 15(3), 5p. http://ufdc.ufl.edu/UF00091523/00710

  Link:

  http://ufdc.ufl.edu/UF00091523/00710

  Abstract:

  Anaerobic digestion of tomato culls produces renewable energy (biogas) and a nutrient-rich effluent. Using the effluent from an anaerobic digester to grow tomato plants could offset the cost of synthetic fertilizer. Effluent from an anaerobic digester fed organic waste was analyzed for major plant nutrients and used as a nutrient medium to grow tomatoes hydroponically. Tomatoes grown using anaerobic digester effluent had a lower performance than those grown with traditional fertilizer. The predominance of nitrogen in the ammonium form, to which tomatoes are sensitive, explains the observed difference in growth. Means of improving performance of tomatoes grown in effluent are discussed.