Characterization of carotenoid pigments from bacterial symbionts of soft-coral Sarcophyton sp. from North Java Sea

Abstract Marine bacteria produce natural pigments; however, the ability of marine bacterial symbionts to produce natural pigments has been less studied. Marine bacteria associated with soft-coral Sarcophyton sp. collected from Karimunjawa Island were successfully isolated and screened to synthesize the carotenoid pigments. This approach has allowed the use of these symbionts as an environmental friendly source of new natural pigments. Out of 33 bacterial isolates, only 4 bacterial symbionts (CBSCP 2-2, CBSCP 2-3, CBSCP 1-1, and CBSCP 2-4), positively contain carotenoid pigments. Molecular identification based on 16S rDNA method showed that bacterial symbionts CBSCP 2-2, CBSCP 2-3, CBSCP 1-1, and CBSCP 2-4 were closely related to Pseudoalteromonas shioyasakiensis, Pseudoalteromonas rubra, Virgibacillus salaries, and Pseudoalteromonas spongiae. Pigment analysis showed that the pigments have been categorized within the groups of carotenoid pigments. Antioxidant activity of pigment extracts was done by measuring inhibitory concentration (IC50) of pigment extract against 2,2-diphenyl-1-picrylhydrazyl (DPPH) solution. The antioxidant activity measurement of CBSCP 1-1, CBSCP 2-2, CBSCP 2-3, and CBSCP 2-4 extract, and β-carotene was 2015, 5017, 2520, 4213, and 1980 mg l−1, respectively