Abstract

In the present study, the phylogenetic analysis of the Streptomyces strain Eri11 isolated from the rhizosphere of Rhizoma Curcumae Longae and the antioxidant activity of the broth cultured with Eri11 were investigated. Analysis of 16S rDNA gene sequences demonstrated that the strains Eri11 was most closely related to representatives of the genera Streptomyces. The total phenols and flavonoids contents in cultured broth were detected to be 13.59 ± 0.17 mg gallic acid equivalent/g and 9.93 ± 0.83 mg rutin equivalent/g, respectively. The cultured broth showed the antioxidant activity against the ABTS (2,2’-Azinobis-3-ethyl benzthiazoline-6-sulfonic acid) free radicals and hydroxyl free radicals with IC50 (The half-inhibitory concentration) of 223.81 ± 24.50 μg/ml and 582.42 ± 83.10 μg/ml respectively. So, it was suggested that the isolated Streptomyces strain Eri11 could be a candidate for the nature resource of the antioxidants.

Key words: Streptomyces, phylogeny, cultured broth, antioxidant activity.