To screen the microorganism that are capable of producing the pigments that can be used for various purpose such as food colorants or for dying purpose. Crowded plate techniques, cross streak method, biochemical characterization of the microogansims, Cytotoxicity studies were performed. While screening for soil isolates 60 soil samples from in and around Ooty and in various parts of Tamilnadu and Kerala were collected. Based on crowded plate and cross steak method, primary screening was done. Five microorganisms were found to possess pigment producing property. Biochemical reactions showed that all microorganisms showed nitrate reduction and starch hydrolysis. Only red and yellow pigments producing microorganism showed melanin formation, and it also showed coagulation and peptonization of milk. The optical density of the cells at 660 nm and absorbance of ethanol solution of red and yellow pigment at 470 nm were measured by using an ultraviolet-visible spectrophotometer. The pH of the culture was measured by a pH meter. Cytotoxicity studies showed that none of the isolates possessed cytotoxic properties in the concentration above 500µg/ml. Because of its higher Cytotoxicity these pigments can be used in dyeing the fabrics and they cannot be used as food colorants.
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