Inhibiting Effects of the Extracts of Isolated Bacteria from Xinjiang on the Ultraviolet Induction of Bacteriophage λ

In this study, the bacterium strains from Takramagan in Xinjiang, which was characteristic with high temperature and strong ultraviolet (UV) radiation in summer, were isolated, purified and identified. The acetone extracts of 39 isolated strains were measured by HPLC and UV-visible detection and their free radical scavenging abilities were determined using UV induction of bacteriophage λ, respectively. The results showed that the main compounds of most extracts were carotenoids and the extracts of 29 strains could protect the bacteriophage λ against UV radiation with different efficiency, the maximum inhibitory rate of which can be up to 81%. By comparison of the strains, it was found that the strains in different genus were obviously different in the protective abilities against UV radiation, and the strain of Methylobacterium showed the strongest among them. Strains with different colors belonging to different genus showed different effect, so did the strains of Kocuria. This paper revealed that carotenoid was one of the key factors for protecting the strains against UV radiation. Furthermore, the UV induction of bacteriophage λ proved to be a very useful model for studying the radiation resistance of different substance.