OPTIMIZATION OF FERMENTATION CONDITIONS FOR RED PIGMENT PRODUCTION FROM ASPERGILLUS FLAVUS UNDER SUBMERGED CULTIVATION AND ANALYSE ITS ANTIOXIDANT PROPERTIES

Aspergillus flavus endophytic fungi was isolated from Ocimum sanctum, produced red pigment. A culture medium composition was established for the production of red pigment, optimum medium composition and environmental conditions were investigated in submerged flask cultures. The optimum carbon, nitrogen sources were determined to be 20g/L of [glucose, sucrose, dextrose] and 5g/L of [ammonium nitrate(NH4NO3), yeast, peptone]. The optimal temperatures [250C,300C 370C] and pH [pH-4.5,5,5.5,6.5] for pigment production in submerged fermentation. Under these conditions peak biomass concentration was 10.7gL -1 in NH4NO3 containing medium in a 15-days culture. The highest volumetric productivity of red pigment was obtained in a batch culture (300C, initial pH-6.5) with a defined medium of the following composition (gL-1 ): dextrose(20) yeast(5). The biomass specific productivity of red pigment was analyzed in extracellular pigment. Extracellular pigment shows maximum absorbance at 750nm. Pigment was characterized with FT-IR shows strong peak at 3421.283nm of phenol group and HPLC resembles 62.978% at the retention time of 9.426. Their antioxidative activities were also estimated by an indication of DPPH, SO, NO and protein content also analyzed. The cytotoxicity of pigment analyzed using Hep-2 cell line and the IC50 value shows 50% inhibition at the concentration of 20µg/ml. Keywords: A.flavus, mycopigment, submerged culture, antioxidant.