Zingiber officinale (Ginger) Extract as a Green Biocide for the Inhibition of Copper Corrosion by Pseudomonas Species

Abstract

This study investigates Zingiber officinale (ginger) extract as a sustainable corrosion inhibitor and antimicrobial agent for copper in a microbiologically active environment containing Pseudomonas aeruginosa. Copper coupons (2.0 × 2.0 × 0.14 cm) were exposed to microbiologically active conditions with and without ginger extract. Phytochemical constituents were identified, and corrosion behaviour was evaluated using weight loss measurements, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS). Antimicrobial activity against P. aeruginosa was assessed via the agar disc diffusion method. Phytochemical analysis confirmed the presence of corrosion-inhibitive bioactive compounds, including gingerol, shogaol, and fatty acids. Copper corrosion was significantly suppressed by the adsorption of extract constituents onto the metal surface. While corrosion rate and weight loss increased with exposure time, both were markedly reduced in the inhibited system. PDP analysis showed that corrosion rate and corrosion current density increased from 2.112 mpy and 4.620 µA cm⁻² in the sterile system to 2.620 mpy and 5.730 µA cm⁻² in the presence of P. aeruginosa. EIS results revealed a pronounced increase in polarization resistance from 98.61 Ω (uninhibited) to 3.15 × 10⁴ Ω with ginger extract. Zingiber officinale extract exhibits strong dual-function performance as a green corrosion inhibitor and antimicrobial agent for copper, offering effective protection in microbiologically influenced corrosion environments.