Antibacterial properties of selected natural dyes against Pseudomonas aeruginosa and Bacillus subtilis

Abstract

Natural dyes extracted from plant samples of Beta vulgaris, Curcuma longa, Terminalia arjuna, Delonix regia, Bixa Orellana, Morus indica, and fungus Penicillium pupurogenum were evaluated against the clinical pathogens of Pseudomonas aeruginosa and Bacillus subtilis. The plant samples were collected from in and around Coimbatore region. The fungal culture was obtained from Department of Agricultural Microbiology, Tamil Nadu Agricultural University, Coimbatore. Clinical pathogens of bacteria were obtained from the PSG Medical College, Coimbatore, Tamil Nadu, India. Agar well diffusion method has been used to determine the antimicrobial activities. The study revealed that five percent methanolic concentration of T. arjuna bark extracts was found to be highly effective against P. aeruginosa with inhibition zone of 14.01 mm, and B. subtilis with 14.50 mm compared to other dye extracts. Streptomycin (30 µg/ml) exhibited zone of inhibition of 16.50 mm. The degree of inhibition varied with the concentrations of compounds extracted from dye powder on the clinical test organisms.