Comparative Study of Oxidative Stress Response Between Gram-positive and Gram-negative Bacteria

15 May
Posted on Author

Authors: Sittie Fatmah M. Abdulrahman, Abdulraffy A. Alikhan, Najibah A. Casim, Janisah O. Hadji Amen, Samson L. Mangin, Junge B. Guillena, Doyne Grace Laparan, Sweet Maraesol Cabrera

Abstract: This study compared the oxidative stress responses of Gram-positive and Gram-negative bacteria exposed to hydrogen peroxide (5–20 mM) and a vitamin C–ferric chloride (FeCl₃) system under varying environmental conditions. Using the disc diffusion method, zones of inhibition were measured for Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa, and Salmonella spp. Gram-negative bacteria were generally more susceptible to hydrogen peroxide, particularly under aerobic conditions, while Gram-positive bacteria showed greater resistance. The vitamin C–FeCl₃ system demonstrated consistent broad-spectrum antibacterial activity across all strains. Environmental factors, especially oxygen availability, influenced oxidative susceptibility. Findings highlight structural and physiological differences affecting bacterial oxidative stress tolerance and suggest the potential of vitamin C–FeCl₃ as an adjunct antimicrobial strategy.

DOI: https://doi.org/10.5281/zenodo.20201650