Characterization of a pigmented Brevundimonas sp. isolated from red mud pond samples of a bauxite mine

Aim: The present study aimed to isolate useful bacterial strains of industrial importance from the red mud pond of Utkal Alumina, Odisha, India. Methodology: Samples were collected, serially diluted and spread on Nutrient Agar medium. An orange-colored bacterium was isolated and subjected to molecular characterization through 16S rDNA analysis followed by phylogenetic analysis. The pigment was isolated and characterized through FTIR study. Antimicrobial and radical scavenging activities were also studied. Results: The isolate was identified as Brevundimonas sp. FTIR study showed the pigment to be a beta-carotene, which significantly increased under salt and pH stress, however, was severely affected under metallic stress conditions. The ethanolic extract showed a moderate antibacterial activity. The pigment showeda good radical scavenging activity of approximately 86 % in 30 min. Interpretation: Species of Brevundimonas have not been reported in red mud ponds. The isolated pigment shows a good radical scavenging activity in vitro. It may be useful for cosmetic industry. Key words: Red mud, 16S rDNA, Alkali tolerant, Beta-carotene, Brevundimonas, FTIR spectroscopy