Effects of Shade on Antibacterial Production in Aloe Vera Plants: A Model Course Based Undergraduate Research Experience for First- and Second-Year Chemistry and Biochemistry Students

Abstract

As a means to promote student engagement in chemistry, this proposed course-based undergraduate research experience (CURE) provides an opportunity for students to research a topic that is particularly prevalent in national public health headlines. Antibiotic resistance is a public health issue of increasing concern as result of the overuse and often misuse of antibiotics. For this reason, it is important to explore a variety of avenues to discover novel antibiotics, including isolating bioactive natural products from plants and other organisms. Organisms such as plants, bacteria, and fungi have long been utilized for their antibacterial properties, but little is known for how the majority of these natural remedies are affected by varying growth conditions. Herein, we propose a method through which students in first- and second-year chemistry or biochemistry laboratory courses can manipulate growth factors of Aloe vera, an antibiotic-producing plant, to probe how those manipulations affect antibiotic production and therefore Aloe vera's effectiveness as an herbal medicine. Aloe vera plants were grown under varying shade conditions, and their gel was extracted and evaluated for antibiotic activity using both a broth microdilution assay and an agar diffusion assay against Staphylococcus aureus and Escherichia coli. Through this model, students are able to develop critical thinking skills, derive a hypothesis, and use analytical and biochemical techniques to evaluate their hypothesis.