Science Honors Research 

Georgia has a large agriculture industry which includes farmers growing beans such as black-eyed peas. One of the main bean pests is bean beetles which can damage crops. Currently the main treatment to prevent bean beetles is pesticides, however, prolonged use or exposure of pesticides can cause health issues such as cancer. Looking at alternative treatments such as probiotics which are safe for consumption and can provide a barrier is important. We hypothesis that the probiotics do not directly kill bean beetles but do diversify their microbiomes. Additionally, they provide black-eyed peas with fortifications needed to endure beetle infestation by disrupting oviposition. We found that it does change their microbiome, however, did not successfully disrupt oviposition. 

This project aimed to study which properties of different artificial surfaces can best inhibit bacterial growth. In the real world, bacteria like to attach to surfaces that are easy to stick to. By allowing the bacteria to attach on a surface for extended periods of time, they can form biofilm. These biofilms can resist the environment and common cleaning practices. By finding out why bacteria are prevented from sticking to certain surfaces, we could use that to mitigate bacterial growth. In this study, I used multiple different sprays and surface coatings to help replicate these artificial surfaces. The sprays include a Hydrophobic Spray, Ceramic Spray, Chitosan Coating, and a Shark Scale Coating. After agar plates were inoculated with the respective coatings, they would sit in in the fridge for up to 24 hours. The very next day, they would be inoculated with the Escherichia coli (K-12). The E.coli (K-12) was the bacteria of choice during this experiment since similar strains of it are common in the real world and it is best used in a labratory setting. After many recorded trials, the Shark Scale Coating best inhibited bacterial growth by far. It grew near 0% of bacteria. This is most likely due to its roughness which makes it harder for bacteria to stick on it. 

This project aimed to study the effects of blocking the plant phytohormone auxin by using the competitive inhibitor auxinole. I am aiming to answer whether TIR1/AFB receptor inhibitors, such as auxinole, impact the growth and development of root vegetables, such as Raphanus sativus (Cherry Belle) variety radishes. In this study, a sample of radishes were grown in a hydroponic system, using water and liquid fertilizer to sustain the plants, and a differing concentration of auxinole to test its effects. After a growth period of 21 days, the radishes were harvested and measured. It was found that as the concentration of auxinole increased within the plant, the root length significantly decreased, while the leaf system and upper half of the plant was generally unaffected. With this system, the root system of plants can be limited, while not significantly impacting the upper half of the plant, having possible applications in gardening and botany.

Our goal was to determine whether Planaria regeneration is reliant on their external mucus barrier. Our hypothesis was that the healthy mucus barrier is essential for planarian regeneration. To test this, we exposed Planaria to 5 different concentrations of loratadine. Over the course of 7 days, we recorded their growth and the time it takes to fully regenerate. We discovered that loratadine slowed down regeneration time. As the concentration of loratadine increased, the planaria in the solution experienced slower growth times and higher mortality. This demonstrates the effects of pharmaceutical runoff, even in medications of low toxicity. This also shows the importance of the mucus barrier in planaria regeneration, suggesting that people should consider using an external mucus barrier when engineering regeneration in other species. 

One of the most common side dishes is Korean cuisine is kimchi, composed of fermented, marinated vegetables. Lactic acid bacteria is known to play a crucial role in the fermentation process and while multiple factors including marinade, pH, temperature, and salt have been studied in relation to kimchi fermentation vegetable variety has remained unexplored. In this study we aimed to gain a better understanding of how bacterial biodiversity differs between vegetable samples. We studied bacterial biodiversity in traditional napa cabbage, bok choy, daikon radish, and carrot kimchi Overall, we found that all bacteria were dominated by Leuconostoc genus. However, the amount of bacteria including Latilactobacilus, Pantoea, Erwinia, and Pseudomonas varied between samples.Furthermore, bok choy  had the highest biodiversity with a Shannon diversity score of .86. Additionally, carrot had the greatest concentration of Pantoea. 

Since the costs of ink are relatively high, especially for developing countries who must import it, since they do not have the infrastructure to mass produce inks finding a more cost-effective alternative is essential. Wood chars (ashes made from burnt wood), made from vast leftovers from various wood industries, are possible candidates for such use, that could facilitate better waste management. The goal of this project was to understand if wood chars could be a suitable alternative to pigments already used in black fountain pen ink, by testing if the wood char pigments are as dark as currently used pigments. To test the darkness of wood char pigments (hardwood charcoal and softwood pigments were chosen) was just as dark if not darker than that of a synthetic mica pigment and lampblack pigment (a historically frequently used pigment) the absorption of the four types for ink samples were measured using a light spectrophotometer. From my results I found that both wood char inks have similar results. The wood char samples were measured having absorption values that were close if not greater than the synthetic samples meaning that the wood char inks were like the synthetic inks in darkness. These results suggest that black inks pigmented wood char could perform at the quality of synthetic inks if not better, and therefore they could be a viable alternative.

Microplastics have been a concern of environmental pollution due to their destructive capacity and properties, and a recent discovery of a smaller size, nanoplastics, has been discovered having even more adverse effects alongside microplastics with its high surface area. As such, it is important to track the sources of plastic pollution such as urban settlements feeding into freshwater rivers, and conduct as much research as possible on the newly discovered plastic particles since this is limited due to insufficient reliable collection and detection methods. My hypothesis for this study is that the concentration of microplastics and nanoplastics would increase within the Chattahoochee River as the population of the nearby city increases. I collected samples from more rural and urban locations, used light absorption techniques for nanoplastic detection with curcumin dye and filtered the samples and observed the resulting filters for microplastics. What I found was that there was no correlation between the nanoplastic concentrations and increasing populations, yet a positive correlation for microplastics, and that light absorption using curcumin dye for a specific wavelength is a viable detection method for nanoplastics.

Oil pollution in marine environments may affect microbial life, but the impact of natural oils versus synthetic pollutants on bacterial growth is not well understood. Looking at the amount of oil spills every year, we wanted to conduct an experiment on how oils spills affect the marine environment. To test this, we scaled down to a lower level and found that Vibrio harveyi is one of the bacteria that habitats in the marine environment. Thus, it was a perfect candidate to test, and to see how the oil spills affect the bacteria we tested the growth of the bacteria which inhibit the synthetic and motor oil. We hypothesized that Vibrio harveyi demonstrate healthy growth in the presence of cod liver oil due to its natural origin and potential nutritional benefits. In contrast, we expected motor oil to inhibit growth because of its synthetic hydrocarbons and toxicity. Our results showed that Vibrio harveyi displayed growth in the cod liver oil treatment group, with absorbance values significantly higher than the control. A thick biofilm was also observed at the surface of these samples, suggesting enhanced bacterial growth. In contrast, the motor oil treatment group exhibited no measurable increase in absorbance, and the cultures remained clear throughout the incubation period, indicating complete inhibition of growth. 

This project aimed to explore how bacterial competition and cooperation affect plant growth in Phaseolus lunatus (lima beans). Our original hypothesis was that co-inoculation with Pseudomonas putida and Bacillus subtilis would enhance nitrogen fixation and plant health when introduced alongside rhizobia. However, due to the absence of visible nodules, we revised our focus to examine plant growth as an indirect indicator of bacterial impact. We inoculated lima bean plants with P. putida, B. subtilis, or both, and compared them to a rhizobia-only control group. Across all treatments, we observed positive effects on plant height, leaf color, and turgor pressure, suggesting that beneficial bacteria improve overall plant health. The co-culture group showed the most consistent improvement in plant vitality, implying a possible synergistic effect. Although our sample size was too small for statistical analysis, descriptive trends support the potential of microbial combinations to enhance legume productivity. This study highlights the importance of microbial interactions in sustainable agriculture and suggests further investigation into how cooperative bacteria can support plant growth, even in the absence of nodulation.