Abstract

Three fungal species Trichoderma psuedo kii niipii, Curvularia lunata, and Alternaria alternate were isolated and produced yellow, olive green, and melanin (peach) color pigment when grown in potato dextrose agar medium (PDA) at stationary condition. Optimum fermentation parameters for maximum pigment production are medium-rice water, pH 5.6, temperature 28C, time of incubation 10 days. Dextrose enhances pigment production whereas ammonium sulfate inhibits the process.

Introduction

Colour is a vital constituent and is probably one of the first characteristics perceived by the senses. With the increasing awareness of toxicity of synthetic colors, demand for pigments from natural sources has increased (Babu and Shenolikar, 1995; Khanna and Singh, 1975). Natural colours are generally extracted from fruits, vegetables, roots, and microorganisms and are often called "biocolours" because of their biological origin (Pattnaik et al., 1997). There is increasing demand for natural colors in the food, pharmaceuticals, cosmetics, textile, and in the printing dye industry.

Microbial pigments are a promising alternative to other color additives extracted from vegetables or animals because they are considered natural, pose no seasonal production problem, and show high productivity. Pigment-producing microorganisms are yeast, fungi, bacteria, microalgae, and are quite common in Nature. Microorganisms produce various pigments like carotenoids, melanins, flavins, monascins (Dufosse L. 2009).

In a study conducted by Chiba et al (2006), a magenta pigment closely related to PhobaHerbarum was grown by a fungal strain in the presence of nylon 6 fibers on Czapek's Agar medium. Nagi et al (2006) described two anthraquinone compounds which were produced by the required culture of Fusarium oxysporum isolated from roots of citrus trees affected with root rot disease. Velmurugan et al (2009) extracted water-soluble pigments from Monascus purputreus, Isaria spp, Emericella spp, Fusarium spp, and Penicillium spp and optimized the process parameters of dyeing leather. Shirata et al (2000) isolated Janthino bacterium lividum from wet silk thread and grew it on wakimoto medium to yield a bluish-purple pigment identified as a mixture of violacein and deoxyviolavein.

Studies have also been carried out to intensify the rate of pigmentation to increase the color yield by incorporating carbon and nitrogen sources in the growth media. The purpose of this research is to enhance color yield by using fungal strains of Trichoderma, Alternaria, and Curvularia lunata on different growth media supplementing it with carbon and nitrogen sources.

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The authors Charu Gupta and Jagriti are associated with the Department of Fabric and Apparel Science, Institute of Home Economics, University of Delhi, Delhi, and Sunita Aggarwal and Nitika Nagpal are associated with the Department of Microbiology, Institute of Home Economics, University of Delhi, Delhi.

The authors have shared their experiment and the outcome