Antioxidant Activities Of Carotenoids From Kineococcus Radiotolerans

A coccus-shaped, orange organism which is anti-radiation, anti-desiccation and antioxidation was isolated from radioactive envirenment. In order to clear the relationship between the antioxidation of Kineococcus radiotolerans and the biological activity of bacteria metabolites in vitro, a research was gaven on extraction, purification, analysis and biological activity of carotenoids in Kineococcus radiotolerans as well as detected the catalase activity of protein preparation. The results show in as follows.Carotenoids from the Kineococcus radiotolerans were solubled in different solvent. To compare of them and found that methanol/ethanol(2:1,V:V) is the better solvent. Analyzed by HPLC and LC-MS for Carotenoids from the Kineococcus radiotolerans’ composition and property, and found that the absorption peak of one product with a molecular formula C48H66O2 has a maximum absorption at 471.9 nm and 501.1 nm, which is a kind of substance similar to the structure of the lycopene, and the other with a molecular formula C24H34 O has a maximum absorption at 464.6 nm.By measurement of ferric reducing antioxidant power(FRAP) and DPPH radical scavenging activities, antioxidant capacities of different carotenoids were investigated. The results showed that the carotenoid extracts of K. radiotolerans had stronger antioxidant capacities in vitro, which about 1.22 of OD700 of FRAP were scavenged at the concentration of 2 μg/ml. Carotenoid extract from DPPH scavenging activity among the tested samples, with 55.19 % DPPH radical were scavenged at the concentration of 0.5 μg/ml. For the catalase activity of protein preparationm, the KR is much more 9 times than the E.coli.Furthermore,the protection of lipid oxidation and protective effects of DNA break caused were compared. Results showed that K. radiotolerans had strong peotective abilities of lipid oxidation which is about 54.29% inhibition of lipid oxidation.The present study generates the basic data for in-depth research of the oxidation and mechanism of K. radiotolerans, and provides a basis for the antioxidantdrug development of medical and health area.