title: Change of Monascus pigment metabolism and secretion in different extractive fermentation process.
abstract: Monascus pigments that were generally produced intracellularly from Monascus spp. are important natural colorants in food industry. In this study, change of pigment metabolism and secretion was investigated through fed-batch extractive fermentation and continuous extractive fermentation. The biomass, secreting rate of pigment and total pigment yield closely correlated with the activated time of extractive fermentation as well as the composition of feeding nutrients. Metal ions played a key role in both the cell growth and pigment metabolism. Nitrogen source was necessary for a high productivity of biomass but not for high pigment yield. Furthermore, fermentation period for the fed-batch extractive fermentation could be reduced by 18.75% with a nitrogen source free feeding medium. Through a 30-day continuous extractive fermentation, the average daily productivity for total pigments reached 74.9 AU day-1with an increase by 32.6 and 296.3% compared to that in a 6-day conventional batch fermentation and a 16-day fed-batch extractive fermentation, respectively. At the meantime, proportions of extracellular pigments increased gradually from 2.7 to 71.3%, and yellow pigments gradually became dominated in both intracellular and extracellular pigments in the end of continuous extractive fermentation. This findings showed that either fed-batch or continuous extractive fermentation acted as a promising method in the efficient production of Monascus pigments.
authors.affiliation: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China.
authors.forename: Gong
authors.initials: G
authors.lastname: Chen
authors.affiliation: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Tang
authors.affiliation: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China.|Dongguan Tianyi Biotechnology Co., Ltd, Dongguan, 523000, China.
authors.forename: Xiaofei
authors.initials: X
authors.lastname: Tian
authors.affiliation: Guangzhou Institute of Microbiology, Guangzhou, 510663, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Qin
authors.affiliation: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou, 510006, China. btzhqwu@scut.edu.cn.
authors.forename: Zhenqiang
authors.initials: Z
authors.lastname: Wu
mesh_terms: D005285:Fermentation; D008823:Micelles; D032741:Monascus; D010860:Pigments, Biological; D013501:Surface-Active Agents
chemical_list: D008823:Micelles; D010860:Pigments, Biological; D013501:Surface-Active Agents
keywords: Extracellular secretion; Extractive fermentation; Monascus pigment; Nonionic surfactant; Spectral characteristics