Abstract. Kusmita L, Nuryadi H, Widyananto PA, Muchlissin S, Sabdono A, Trianto A, Radjasa OK. 2021. Bioactivity of carotenoid produced by soft coral symbiotic microorganisms from Panjang and Karimunjawa Island, Centra Java, Indonesia. Biodiversitas 22: 732-740. The diversity of soft corals is more varied in waters. One of the characteristics of soft corals is the production of secondary metabolites, i. i.e. carotenoids. Carotenoids are phytonutrients found in the cells of a wide variety of plants, algae, and bacteria as secondary metabolic compounds with antioxidant functions. Carotenoid biosynthesis is strongly influenced by the environment in which the producing organism grows. This study was aimed to uncover the antioxidant and anti-ultraviolet activities of carotenoids produced by soft coral symbiotic microorganisms in the waters surrounding the Panjang and Karimunjawa Islands in the North Java Sea, Indonesia. The parameters observed included water quality, antioxidant activity, and anti-ultraviolet activity. The results indicated that the water quality at Panjang Island did not meet quality standards (including salinity, visibility, dissolved oxygen, ammonia, and nitrate) while that at Karimunjawa did. The diversity of soft corals was more varied at Karimunjawa Island than at Panjang Island. In contrast to the bioactivity, the carotenoid extracts from the Panjang Island soft coral symbiotic microorganisms showed higher activity than those from Karimunjawa Island microorganisms. The highest antioxidant activity was found in the bacterial isolate 19.PP.Sc1.6 from Panjang Island and was identified based on the 16S rRNA gene as Virgibacillus salarius, with 99% similarity.

Soft corals have been known to produce secondary metabolites, some of which may have anticancer, antifouling, antibacterial and antioxidants activity. It has been suggested that natural products from marine invertebrates have striking similarities to metabolites of their association microorganisms. Symbiont bacteria on soft coral can produce bioactive compounds that play an important role in chemical ecology and as a marine natural product. Marine bacteria associated with soft coral collected from Jepara were successfully isolated on medium ZoBell 2216E and screened to synthesize the pigment. This approach has allowed the use of this organism as an environmentally friendly alternative source of new natural pigment. This study found 25 bacterial isolates from 6 types of soft coral. Out of 25 bacterial isolates, only 3 bacterium, positively contains pigments. Four isolates, PCl 1, PS2 1, and PSa 2. Pigments analysis with UV spectrophotometric method showed the wavelength of pigments were in the range 300-600 nm. Genomic DNA was isolated from these colonies and nested PCR of the DNA was performed to amplify the 16S rDNA. Antioxidant activity was tested with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) method. From the results of molecular identification by 16S rDNA method, it was shown that bacterium PCl 1, PS2 1, and PSa 2 was closely related to Pseudomonas stutzeri, Ponticoccus gilvus, Bacillus marisflavi with 99%, 99and 98% homology value. Antioxidant activity is as follows: PCl 1>PS2 1>PSA 2.

Tubercolusis is a disease that attacks the lungs. The disease is caused by the bacterium mycobacterium tubercolusis. The bacteria mycobacterium tubercolusis can be killed by antibiotics. However, continuous use of antibiotics can cause bacterial resistance. So we need to find new drugs that can prevent multi-drug resistant tuberculosis. This study aims to determine the antibacterial activity of MDR TB from soft coral symbiont bacteria Lobophytum sp. There were 6 bacterial isolates obtained from soft coral Lobophytum sp. One isolate from Lobophytum-associated bacteria were successfully screened for antimycobacterial against MDR TB bacteria. PLO2 was found to inhibit the growth of MDR TB (MDR TB strain SIRE and R). Based on the results of identification with PCR, soft coral symbionts of PLO2 was closely related to Virgibacillus marismortui with homology of 99%.