Discipline: Biological Sciences
Room: Exhibit Hall A
Jada Bibb - Alabama Agricultural and Mechanical University
Co-Author(s): Iyninoluwa Sofowora, Alabama Agricultural and Mechanical University, Huntsville, AL. Manjula Bomma, Alabama Agricultural and Mechanical University, Huntsville, AL.
Vinegar has been utilized for medicinal purposes throughout history. Vinegar is formed when ethyl alcohol is converted into acetic acid. A specific vinegar, apple cider vinegar (ACV) is produced from fermented apple juice with a low acidity composition of 5% acetic acid. ACV has been found to have antimicrobial properties and has recently been used as a weight-loss supplement. Although there are known health benefits of ACV as a dietary supplement, the effect of ACV with direct contact to Gram- positive pathogenic bacteria, as well as, probiotic bacteria have not been identified. The objective of this study is to determine the antimicrobial activity of unfiltered Braggs ACV on three Gram-positive, Bacillus brevis and Bacillus subtilis globigii, and probiotic bacteria Lactobacillus acidophilus, and Gram-negative, Escherichia coli. The bacteria (McFarland standard of 10⁵ CFU) were cultured for 24 hours at 37 0C in Mueller Hinton Broth and physiological saline using a computerized Bioscreen assay to measure ACV effects on the growth rate of bacteria. This was determined by measuring their inhibitory effects. Ampicillin at 10µg/mL, sterile Mueller Hinton Broth and saline were used as the positive and negative controls, respectively. Our hypothesis is that the unfiltered ACV will have varying inhibitory effects on the test bacteria depending on the concentrations. The results of all the experiments were expressed as the mean value of three independent replicates ± the standard deviation (SD). In comparison to untreated broth grown bacteria (control), there was reduction in OD values for broth grown test bacteria treated with diluted ACV (1:1) had the highest growth reduction of 49% of Bacillus subtilis globigii and 33 % growth inhibition on Bacillus brevis. A similar effect was observed with Lactobacillus acidophilus (probiotic bacteria) however there was no difference in growth inhibition for both concentrations of ACV. There was no effect of undiluted ACV against saline grown probiotic bacteria. the effects of ACV on Escherichia coli was slightly different. The undiluted ACV had 9% growth reduction while 1:1 ACV had 16% growth reduction. Our results indicates that the undiluted and diluted ACV could be utilized as alternative source of antimicrobials with the ability to inhibit the growth of probiotics. Our future work will focus on a variety of commercial ACV combinations on antibiotic resistant bacteria and reduction of its effects on the growth of probiotics. References: Yagnik, Darshna & Serafim, Vlad & Shah, Ajit. Antimicrobial activity of apple cider vinegar against Escherichia coli, Staphylococcus aureus and Candida albicans; downregulating cytokine and microbial protein expression. Scientific Reports. 8. 10.1038/s41598-017-18618-x. A.P. Fraise, M.A.C. Wilkinson, C.R. Bradley, B. Oppenheim, N. Moiemen. The antibacterial activity and stability of acetic acid. Journal of Hospital Infection. Volume 84, Issue 4, 2013. Pages 329-331. ISSN 0195-6701.
Funder Acknowledgement(s): This work is supported by a grant from the USDA National Institute of Food and Agriculture & Advancing Success in STEM Undergraduate Research and Education (ASSURE) NSF no. 1436572. We acknowledge the support given by Alabama Louis Stokes Alliance for Minority Participation (ALSAMP) program.
Faculty Advisor: Dr. Florence Okafor, Florence.firstname.lastname@example.org
Role: I inoculated the bacteria in the Mueller Hinton broth and physiological saline used to perform the experiment, as well as, assisted with the Bioscreen assay. I also assisted with analyzing the results of the study.