Identification, Characterization and Antioxidant Activity of YellowishOrange Pigments Actinobacteria.

Actinobacteria are Gram-positive bacteria that can produce various secondary metabolites, including pigments that have potential as antioxidants. This study assessed the characteristics of yellowish-orange pigmented actinobacteria. The antioxidant activity of their extract pigment was tested by DPPH and analyzed by LC-MS. The identification results based on the 16S rRNA gene showed that the HRA isolate had 99.91% similarity value to Streptomyces gramineus JR-43, the HVA isolate had 99.22% similarities value to S. tendae ATCC 19812 and the HVB isolate had 81.18% similarities value to Rhodococcus ruber DSM 43338. Meanwhile, AGM 2.2 and 2.3 isolates had similarities to S. xanthophaeus NRRL B-5414 with similarity values of 98.95% and 99.82%, respectively. The Inhibitory Concentration (IC50) of actinobacterial crude extract pigments ranges from 53.38 µg/ml to 184.38 µg/ml. The HVB isolates with the major compound luteolin, have the highest antioxidant activity. The crude extract pigment of H [ABSTRACT FROM AUTHOR]