Enhancement of colour yield of pigment produced by Trichoderma pseudo kii nii pii, Alternaria alternata and Curvularia lunata
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 sulphate inhibits the process.
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 colours, demand for pigments from natural sources has increased (Babu and Shenolikar, 1995; Khannaanf 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 colours in the food, pharmaceuticals, cosmetics, textile and in printing dye industry. Microbial pigments are a promising alternative to other colour additive 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, micro algae and are quite common in Nature. Microorganisms produce various pigments like carotenoids, melanins, flavins, monascins (DufosseL. 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 fibres on Czapek's Agar medium. Nagi et al (2006) described two anthraquinone compounds which were produced by required culture of Fusariumoxysporum isolated from roots of citrus trees affected with roots not disease. Velmurugan et al (2009), extracted water soluble pigments from Monascuspurputreus, Isariaspp, Emericellaspp, Fusariumspp and Penicilliumspp and optimized the process parameters of dyeing leather. Shirata et al (2000) isolated Janthino bacterium lividum from wet seek thread and grew it n 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 colour yield by incorporating carbon and nitrogen sources in the growth media. The purpose of this research is to enhance colour yield by using fungal strains of Trichoderma, Alternaria and Curvularia lunata on different growth media supplementing it with carbon and nitrogen sources.
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