Production and characterization of orange pigment produced by Halophilic bacterium Salinococcus roseus isolated from Abattoir soil

Abstract

There was little information about the nature of orange pigment produced by Salinococcus roseus. Therefore this study aimed to optimize and characterize the orange pigment produced by Salinococcus roseus isolated from abattoir soil. The soil collected from abattoir was screened for isolation and identification of orange pigment-producing bacteria. The resulting orange pigmented colonies were subjected to biochemical and molecular identification. The phylogenetic analysis of bacterial isolate was carried out using MEGA 6 software. Ethanol was used for pigment extraction and extracted pigment was characterized using UV-Visible spectroscopy and Fourier Transformed Infrared (FTIR) spectroscopy. The stability of the pigment was also determined toward pH and temperature. The sequence analysis of 16SrDNA of the isolate showed maximum identity of 100% to Salinococcus roseus. Of various parameters optimized, a temperature of 37oC, pH 7, nutrient broth, 96 hours incubation and under shaking condition of 100rpm/min was found to be optimum for orange pigment production. The UV-Visible spectroscopy at wavelength of 440nm showed characteristic corresponds to zeaxanthin. The FTIR spectroscopy revealed the presence of following functional groups C-O-C (900cm-1), C-H (710cm-1), C=O (1430cm-1), C=C (1610cm-1) and OH (3380cm-1) correspond to zeaxanthin. The pigment was found stable at pH 13 and at temperature of 200oC. This indicated its suitability for various industrial applications such as textile industries.