Studies on Pigment Production by Microorganisms Using Raw
Materials of Agro-industrial Origin

Abstract

The recent awareness in human safety and environmental conservation has created fresh enthusiasm for natural sources of pigments. Compared to synthetic pigments, microbial pigments shows better biodegradability and higher compatibility with the environment, and have numerous applications from food to cosmetics. Identification of new microbial sources, utilization of low cost substrates and optimization of process parameters are the areas under focus towards economical pigment production. The present study aimed at screening and identification of microbial isolates from soil and water, which are having pigment producing ability. Efforts have been made to cultivate them on numerous cheaper and inexpensive substrates with no special
conditions and supplements for effective pigment production. Furthermore, two carotenoid producing strains were also exploited on numerous inexpensive substrates at ambient conditions for pigment metabolites. While analyzing pigment metabolites in all cases, key parameters influencing pigment production by respective strains were optimized by utilizing statistical techniques like Taguchi method and response surface approaches wherever needed. The conditions for enhanced pigment production were established employing microbial isolates and purchase strains individually. The melanin producing Pseudomonas guinea, (bacterial strain) was
isolated from marine water sample and was employed on vegetable waste for effective pigment production. Another strain of Bacillus safensis was isolated from garden soil and showed its ability to produce melanin on fruit waste extract (FWE). It is noteworthy that both melanins
produced from marine and soil isolates showed antioxidant, photoprotective and metal ion chelation activities. Addressing garden soil, a new carotenoid producing bacterial strain Bacillus clausii was screened and cultivated on FWE for high yield pigment production. The pigment produced by this strain was observed to be a β-carotenoid type and its stability towards thermal treatment was also evaluated. Eying on the significance of carotenoids, microorganisms (Rhodotorula rubra, Xanthophyllomyces dendrorhous) in their developmental stage were purchased and studied for pigment production on various residues as sole substrates. The obtained yeasts showed improved carotenoids yield i.e. torularhodin and astaxanthin respectively on FWE. In a nut shell we could conclude that there is a huge scope for industrial scale production of Melanin and Carotinoid using easily available agro-industrial raw materials such
as rice powder and fruit waste extract (FWE).