Microbial Influenced Corrosion of Copper and Inhibiting Effects of Capsicum annuum Extracts

This study investigated the potential of Capsicum annuum extract as a green biocide and corrosion inhibitor for copper in the presence of Desulfotomaculum sp, a sulfate-reducing bacterium implicated in biocorrosion. The phytochemical analysis of C. annuum revealed that the extract is rich in bioactive compounds, including capsaicinoids, fatty acids, and terpenes. The antimicrobial activity of the extract against Desulfotomaculum sp was evaluated using well-in-agar diffusion assay, which showed significant dose-dependent inhibition zones. The corrosion inhibition properties of the extract were assessed by monitoring the weight loss and corrosion rates of copper coupons coated with the extract in both control media and media containing Desulfotomaculum sp. The results showed that C. annuum extract, effectively reduced the corrosion rates of copper coupons, with the greatest inhibition observed in the control medium. The study proposes a dual mechanism of action, where the antimicrobial compounds in the extract inhibit the growth and metabolic activities of Desulfotomaculum sp, reducing the production of corrosive metabolites, while simultaneously forming a protective film or exhibiting antioxidant properties on the copper surface, directly inhibiting the corrosion process. These findings highlight the promising potential of C. annuum extract as a green, sustainable, and cost-effective solution for biocorrosion control in various industrial sectors.