title: The relationship between the violet pigment PP-V production and intracellular ammonium level in Penicillium purpurogenum.
abstract: Penicillium purpurogenum is the fungus that produces an azaphilone pigment. However, details about the pigment biosynthesis pathway are unknown. The violet pigment PP-V is the one of the main pigments biosynthesized by this fungus. This pigment contains an amino group in a pyran ring as its core structure. We focused on this pigment and examined the relationship between intracellular ammonium concentration and pigment production using glutamine as a nitrogen source. The intracellular ammonium level decreased about 1.5-fold in conditions favoring PP-V production. Moreover, P. purpurogenum was transferred to medium in which it commonly produces the related pigment PP-O after cultivating it in the presence or absence of glutamine to investigate whether this fungus biosynthesizes PP-V using surplus ammonium in cells. Only mycelia cultured in medium containing 10 mM glutamine produced the violet pigment, and simultaneously intracellular ammonium levels decreased under this condition. From comparisons of the amount of PP-V that was secreted with quantity of surplus intracellular ammonium, it is suggested that P. purpurogenum maintains ammonium homeostasis by excreting waste ammonium as PP-V.
authors.affiliation: Graduate School of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kojima
authors.affiliation: Depertment of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Teppei
authors.initials: T
authors.lastname: Arai
authors.affiliation: Depertment of Food Bioscience and Biotechnology, College of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.|Graduate School of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Matsufuji
authors.affiliation: Depertment of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.|Graduate School of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Kasumi
authors.affiliation: Depertment of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.|Graduate School of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan.
authors.forename: Taisuke
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: Depertment of Chemistry and Life Science, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan. j-ogihara@brs.nihon-u.ac.jp.|Graduate School of Bioresource Sciences, Nihon University, 1866 Kameino, Fujisawa, Kanagawa, 252-0880, Japan. j-ogihara@brs.nihon-u.ac.jp.
authors.forename: Jun
authors.initials: J
authors.lastname: Ogihara
keywords: Ammonium; Penicillium purpurogenum; Pigment; Primary metabolism; Secondary metabolism