Turning Stress Into Color: Enhancing Pyocyanin Yield via Solvent-Induced Responses in Pseudomonas aeruginosa

Bacterial pigments are emerging as sustainable alternatives to synthetic dyes, with potential applications in textiles. Pyocyanin, a vivid blue pigment produced by Pseudomonas aeruginosa, is biodegradable and easily extractable and exhibits strong antimicrobial activity against Staphylococcus aureus, Escherichia coli, Fusarium graminearum, and Candida albicans, making it a promising biodye.

This study investigated the use of stress-inducing agents (toluene, acetone, ethanol, and their mixtures) to enhance pyocyanin production. Pseudomonas aeruginosa NCTC 12903 was cultured in nutrient broth for seven days. Organic solvents were added 24 h after inoculation to trigger a defensive metabolic response. Visible pigment accumulation after one week confirmed successful induction. Among the tested conditions, 0.1% (v/v) ethanol yielded the highest pigment levels. The extracted pyocyanin was applied to multifiber fabric, demonstrating its effectiveness as a sustainable, functional textile dye.

Ethanol, being relatively biodegradable and less toxic than conventional dye precursors, requires only small amounts to stimulate pigment production. Recovery strategies, including rotary evaporation, further support the environmental viability of this process.