title: Effects and Mechanism of Blue Light on Monascus in Liquid Fermentation.
abstract: The effect of light onMonascusand the underlying mechanism have received a great deal of interest for the industrial application ofMonascuspigments. In this study, we have examined the effects of blue light on the culture morphology, mycelium growth, pigments, and citrinin yield ofMonascusin liquid-state and oscillation fermentation, and explored the mechanism at a physiological level. It was found that blue light affected the colony morphology, the composition (chitin content), and permeability of theMonascusmycelium cell wall in static liquid culture, which indicates blue light benefits pigments secreting from aerial mycelium to culture medium. In liquid oscillation fermentation, the yields ofMonascuspigments in fermentation broth (darkness 1741 U/g, blue light 2206 U/g) and mycelium (darkness 2442 U/g, blue light 1900 U/g) cultured under blue light and darkness are different. The total pigments produced per gram ofMonascusmycelium under blue light was also higher (4663 U/g) than that in darkness (4352 U/g). However, the production of citrinin (88 μg/g) under blue light was evidently lower than that in darkness (150 μg/g). According to the degradation of citrinin caused by blue light and hydrogen peroxide, it can be concluded that blue light could degrade citrinin and inhibit the catalase activity ofMonascusmycelium, subsequently suppressing the decomposition of hydrogen peroxide, which is the active species that degrades citrinin.
authors.affiliation: College of Food Science & Engineering, Xuchang University, Xuchang 461000, China. xiaoweizhang1982@163.com.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Food Science & Engineering, Xuchang University, Xuchang 461000, China. m13298265891@163.com.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Liu
authors.affiliation: College of Food Science & Engineering, Xuchang University, Xuchang 461000, China. m15993640173@163.com.
authors.forename: Xiying
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, College of Advanced Materials and Energy, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang 461000, China. cjhyinian@163.com.
authors.forename: Junhui
authors.initials: J
authors.lastname: Cai
authors.affiliation: Department of Food Biotechnology, Tianjin University of Science and Technology, 1038 Dagu South Road, Hexi District, Tianjin 300222, China. clw123@tust.edu.cn.
authors.forename: Changlu
authors.initials: C
authors.lastname: Wang
authors.affiliation: Key Laboratory of Micro-Nano Materials for Energy Storage and Conversion of Henan Province, College of Advanced Materials and Energy, Institute of Surface Micro and Nano Materials, Xuchang University, Xuchang 461000, China. heweiweixcu@gmail.com.
authors.forename: Weiwei
authors.initials: W
authors.lastname: He
mesh_terms: D002851:Chromatography, High Pressure Liquid; D002953:Citrinin / Q000096:biosynthesis; D003470:Culture Media; D005285:Fermentation; D005944:Glucosamine / Q000737:chemistry; D006861:Hydrogen Peroxide; D008027:Light; D032741:Monascus / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects*; D025282:Mycelium / Q000378:metabolism; D010641:Phenotype; D010860:Pigments, Biological / Q000096:biosynthesis
chemical_list: D003470:Culture Media; D010860:Pigments, Biological; D002953:Citrinin; D006861:Hydrogen Peroxide; D005944:Glucosamine
keywords: Monascus; blue light; catalase; citrinin yield; photodegradation