THE CORRELATION BETWEEN REDOX ACTIVITY AND ANTIMICROBIAL PROPERTIES OF PYOCYANIN FROM Pseudomonas aeruginosa

Abstract

Pseudomonas aeruginosa, a metabolically versatile gram-negative bacterium, has garnered attention for its ability to thrive in diverse environments and its capacity to produce pyocyanin, a secondary metabolite with multifunctional properties. Pyocyanin, a redox-active phenazine compound, plays a critical role in mediating the ecological competitiveness of P. aeruginosa through its antimicrobial, biofilm-modulating, and reactive oxygen species (ROS)-generating activities. Beyond its contributions to bacterial virulence, pyocyanin demonstrates significant potential in various industrial and biomedical applications due to its redox properties and ability to function under diverse environmental conditions. This study investigates the electrochemical behaviour and pH-dependent antimicrobial activity of pyocyanin to evaluate its applicability in environmental and medical fields. Soil-derived P. aeruginosa isolates were cultured for pyocyanin (PYO) production, and the pigment was characterized using UV-visible spectroscopy to get its spectral integrity. Electrochemical analysis through cyclic voltammetry revealed enhanced redox activity in acidic environments and stable functionality in alkaline conditions. Antimicrobial assays demonstrated that pyocyanin exhibited optimal activity at neutral to slightly alkaline pH, effectively inhibiting bacterial and fungal growth, while extreme acidic conditions reduced its efficacy. The findings highlight pyocyanins versatility as both a redox mediator and an antimicrobial agent. In medical contexts, its pH-sensitive activity aligns well with physiological conditions, offering promise for combating multidrug-resistant pathogens. Future optimization of pyocyanin biosynthesis, particularly through cost-effective and scalable methods, could unlock its full potential in biotechnological and therapeutic innovations.