Production and Antimicrobial Activities of Pyocyanin Extracts from Pseudomonas aeruginosa

Pyocyanin is a blue-green phenazine pigment synthesized by Pseudomonas aeruginosa that has significant biotechnological applications. The present study aims to investigate pyocyanin extracts of multi-drug resistant P. aeruginosa isolates sourced from hospital wastewater and evaluate their antimicrobial activity against a panel of clinically relevant pathogens such as Staphylococcus aureus, Salmonella typhi, Achromobacter xylosoxidans and Candida albicans. Nutrient broth and King’s A broth supplemented with 1% nutrient supplements such as rice water and groundnut cake powder were used as a production medium. Extracted pyocyanin was confirmed by FTIR analysis. The isolates P8 and P9 demonstrated of varying concentrations of pyocyanin in different media. Isolate P8 showed maximum pyocyanin production in King’s A broth compared to nutrient broth with pyocyanin yields 14.34 (µg/mL) and 5.63 (µg/mL), respectively, without the nutrient supplements. Preliminary antimicrobial activity of the pyocyanin extracts exhibited substantial inhibition of tested bacterial culture at a concentration of 25 mg/µl; however, did not show any antifungal activity against tested fungi.