title: Controlling composition and color characteristics of Monascus pigments by pH and nitrogen sources in submerged fermentation.
abstract: Submerged fermentations of Monascus anka were performed with different nitrogen sources at different pH in 3 L bioreactors. The results revealed that the Monascus pigments dominated by different color components (yellow pigments, orange pigments or red pigments) could be selectively produced through pH control and nitrogen source selection. A large amount of intracellular pigments dominated by orange pigments and a small amount of water-soluble extracellular yellow pigments were produced at low pH (pH 2.5 and 4.0), independently of the nitrogen source employed. At higher pH (pH 6.5), the role of the nitrogen source became more significant. In particular, when ammonium sulfate was used as nitrogen source, the intracellular pigments were dominated by red pigments with a small amount of yellow pigments. Conversely, when peptone was used, intracellular pigments were dominated by yellow pigments with a few red pigments derivatives. Neither the presence of peptone nor ammonium sulfate promoted the production of intracellular orange pigments while extracellular pigments with an orangish red color were observed in both cases, with a higher yield when peptone was used. Two-stage pH control fermentation was then performed to improve desirable pigments yield and further investigate the effect of pH and nitrogen sources on pigments composition. These results provide a useful strategy to produce Monascus pigments with different composition and different color characteristics.
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
authors: Kan
authors: K
authors: Shi
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
authors: Da
authors: D
authors: Song
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
authors: Gong
authors: G
authors: Chen
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
authors: Marco
authors: M
authors: Pistolozzi
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China. Electronic address: btzhqwu@163.com.
authors: Zhenqiang
authors: Z
authors: Wu
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou 510006, PR China.
authors: Lei
authors: L
authors: Quan
mesh_terms: D000645:Ammonium Sulfate / Q000378:metabolism; D019149:Bioreactors; D003116:Color; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D032741:Monascus / Q000378:metabolism*; D009584:Nitrogen / Q000378:metabolism*; D010461:Peptones / Q000378:metabolism; D010860:Pigments, Biological / Q000737:chemistry* / Q000378:metabolism*; D012995:Solubility; D014867:Water / Q000737:chemistry
chemical_list: D010461:Peptones; D010860:Pigments, Biological; D014867:Water; D009584:Nitrogen; D000645:Ammonium Sulfate
keywords: Color characteristics; Monascus pigments composition; Nitrogen sources; Submerged fermentation; pH