A novel carotenoids-producing marine bacterium from noble scallop Chlamys nobilis and antioxidant activities of its carotenoid compositions

Marine bacteria produce many bioactive compounds, including carotenoids. However, the quality of bacterium carotenoids is relatively unknown. Therefore, in this study, a novel carotenoids-producing bacterium Brevundimonas scallop Zheng & Liu was isolated from Chlamys nobilis. The genome of the isolate was analyzed, carotenoid compounds were screened using HPLC-MS and the carotenoid production in B. scallop was monitored. The results revealed that the genome of B. scallop contained a carotenoid synthesis gene cluster, which involved in astaxanthin and hydroxy-astaxanthin biosynthesis. The 2,2'-dihydroxy-astaxanthin was the major carotenoid produced by B. scallop. The optimum culture condition for the highest carotenoids production (1303.62 +/- 61.06 mu g/g dry cells) for B. scallop was at temperature and salinity of 20 degrees C and 3% salt, respectively, in 10 g/L glucose as carbon source. The results showed the B. scallop is a new carotenoids resource in marine bivalve, which has an excellent antioxidative activity and potential industrial use.