Main Article Content
Abstract
A pigment producing bacterium from coir retting effluent was isolated and it was identified as Serratia marcescens MTCC 10774. The pigment production of the bacterium was tested under different culture conditions. The bacteria were isolated in King B agar media. The pigment production and growth were also observed in liquid culture of King B medium. Pigment production was found maximum at 25°C, neutral pH and 0.25% sodium chloride. Compared to the wild strain, pigment production was reduced in UV and ethidium bromide treated mutants. Pink pigment prodigiosin from the bacteria was more soluble in ethanol than other solvents verified by this study. The pigment was not toxic to higher organisms especially aquatic species. Dyeing was observed at its maximum when the fabrics and polypropylene plastic were immersed in dye bath at 160°C. The dyeing efficiency was high in polyester. The fading of fabrics against washing with detergents and rubbing was found to be low. The maximum colour fastness against sunlight was observed in cotton. Among the adjuvant used, phosphoric acid was found to suppress fading by sunlight. It was found that pre-treatment with thiourea solution considerably reduced the fading of the pink colour due to sunlight. Moreover, since mass culture of the bacteria is possible, the dyeing pigment can be produced cheaply.