The Effect of Different Concentrations of Bacillus subtilis on Spirulina platensis Growth in an Environment with Glyphosate

Overview

Red tides are a significant issue along the coasts of several countries around the world. These red tides consist of algae that grow at an expedited rate, resulting in many issues for the surrounding environment. The purpose of this study was to see if add ing Bacillus subtilis at different concentrations would decrease Spirulina platensis growth in an environment with glyphosate. It was hypothesized that in an environment with glyphosate, a 30% B. subtilis solution would decrease S. platensis growth at a greater rate than a 0% or 15% solution because B. subtilis has the ability to degrade glyphosate and reduce the amount of nutrients available for S. platensis. To conduct this study, different concentrations of B. subtilis were made by diluting a bacterial solution in distilled water, respectively. Then, 5 mL of the B. subtilis solution, S. platensis, and glyphosate were added into a petri dish and placed in a dark drawer for 96 hours. Afterward, a SpectroVis spectrophotometer was used to measure the absorban ce of the S. platensis in each petri dish as an indicator for colony density. The results showed that adding B. subtilis at different concentrations decreased S. platensis growth by 80.4% in the 15% solution and 88.9% in the 30% solution. A subsequent one-way ANOVA test showed the data was statistically significant since F(2, 87) = 374.46, p<0.001, which means there is enough evidence to reject the null hypothesis. The results indicate that B. subtilis was successfully able to decrease S. platenis growth by degrading the glyphosate. Reducing Tracheal Complications in Endotracheal Intubation Patients Using Automated Cuff Pressure Modulation Shrihan Ganesh Babu Spring Valley High School, Columbia SC Dr. Michelle Spigner, Spring Valley High School Endotracheal tube intubation is the third most frequent procedure, performed approximately 13 -20 million times yearly in the United States (Mosier et al., 2020). Despite the regularity of the procedure, intubation - related complications such as tracheal injuries, laryngeal injuries, and ventilator-associated pneumonia are ubiquitous due to improper cuff pressure management methods (Ganti et al., 2018). Current techniques, such as the pilot-balloon and minimal-leak technique, have proven ineffective and inconsistent in managing pressure. As a result, over 71.6% of intubation patients have abnormally high cuff pressures (Ramírez, 2014). Therefore, the purpose of this research was to design an endotracheal tube with automated cuff pressure modulation synced with the respiratory cycle; increasing and decreasing cuff pressures as patients inhale and exhale theoretically relieves pressures placed on the trachea during intubation and can reduce many of the complications associated with endotracheal tubes. The device was designed using two pressure sensors to evaluate the instantaneous pressure and cuff pressure, two DC motors to inflate and deflate the cuff, and an Arduino microcontroller to control the units. To test the device for its functionality, air was blown into the tube to simulate intubation and the respiratory cycle, and the responding cuff pressure was monitored. The results found that the endotracheal tube successfully automatically modulated the cuff pressure to pressures of 25 cmH ₂O and 14-15 cmH₂O with the respiratory cycle. Therefore, the proof -of- concept design to modulate the cuff pressure of endotracheal tubes presented a viable solution to reduce intubation-related injuries for millions of patients across the world.

Competition history

• JSHS 2024 Category not listed

Resources

• National JSHS abstract book ↗

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