A Marine Derived Carotenoid from Planococcus Maritimus KA01 with Promising Bioactivity
Marine ecosystems are recognized as rich reservoirs of bioactive pigment-producing microorganisms with potential industrial applications. In this study, an orange-pigmented bacterium was isolated from marine sediment collected from Colachel, Tamil Nadu, India, and identified as Planococcus maritimus KA01 through 16S rRNA sequencing and phylogenetic analysis. Optimization of culture conditions showed that maximum carotenoid production occurred at 25 °C, pH 7, after 96 h of incubation, with 1.0% NaCl, glucose as the carbon source, and under shaking conditions. Methanol showed the highest efficiency solvent for pigment extraction. Spectral characterization via UV-Vis, FTIR, and GC-MS suggested the presence of carotenoid-like compounds, with squalene identified as a major metabolite. The pigment extract exhibited antibacterial activity, with lower MIC and MBC values against Staphylococcus aureus compared with Pseudomonas aeruginosa, indicating greater susceptibility of Gram-positive bacteria under the tested conditions. Antioxidant analysis using the DPPH assay demonstrated dose-dependent radical-scavenging activity. Overall, the study suggests that P. maritimus KA01 is a promising source of carotenoid-containing pigments with antimicrobial and antioxidant properties. Further studies involving purification, toxicity assessment, and large-scale production are required to establish potential applications.