Effect of mutagenesis treatment on antimicrobial and antioxidant activities of pigments extracted from Rhodotorula glutinis

The coloring of textiles, leather, food and other materials with natural dyes and pigments is receiving great attraction due to their non-toxic and non-allergic nature. Aim of this research was to study effect of treatment with the mutagens (ultraviolet (UV) irradiation and sodium azide (SA)) on Rhodotorula glutinis through targeted production of carotenoid, antimicrobial and antioxidant activities. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of pigment extracted from R. glutinis were evaluated by agar dilution method. Antioxidant activity of pigments extracted from R. glutinis was determined by DPPH method. The examined bacteria, especially gram-positive bacteria, had higher sensitivity to the pigments extracted from R. glutinis compared to the tested molds, so that Bacillus cereus and Alternaria citri had the highest and lowest sensitivity to the pigments, respectively. The pigments extracted from R. glutinis treated with the mutagens, especially SA, had lethal effect on all the tested microorganisms and as well as more antimicrobial and antioxidant activity than the pigment extracted from the wild strain.