Abstract: The purpose of this study was to identify a red pigment produced by Micrococcus roseus A-04 which was isolated from an oil-polluted soil and water and preserved by our laboratory.The factors influencing on the pigments’ stability were analyzed by using the single factor experiment.Moreover,a response surface methodology with three factors and three levels was used in this study to investigate the key factors that influenced pigments’ stability based on single factor analyses.The results showed that the red pigment from Micrococcus roseus A-04 belongs to carotenoids on the basis of spectroscopic analysis.The single factor experiment showed that the pigment exhibited high stability under a variety of conditions,and did not fade after a long time.This article explored the interactions between the factors and the pigments’ stability.The results showed that temperature,pH and solvent are the key factors,and the interaction between temperature and solvent effects the stability of pigment obviously.Under 80 ℃ and pH between 5 and 8,the lower temperature and stronger polarity is,the more stability the pigments will be.This work lays a foundation for the development and application of this pigment.

Key words: Micrococcus roseus, natural pigment, stability, response surface analysis