title: Aspergillus oryzae-based cell factory for direct kojic acid production from cellulose.
abstract: BACKGROUND
  Kojic acid (5-Hydroxy-2-(hydroxymethyl)-4-pyrone) is one of the major secondary metabolites in Aspergillus oryzae. It is widely used in food, pharmaceuticals, and cosmetics. The production cost, however, is too high for its use in many applications. Thus, an efficient and cost-effective kojic acid production process would be valuable. However, little is known about the complete set of genes for kojic acid production. Currently, kojic acid is produced from glucose. The efficient production of kojic acid using cellulose as an inexpensive substrate would help establish cost-effective kojic acid production.
  
  
  RESULTS
  A kojic acid transcription factor gene over-expressing the A. oryzae strain was constructed. Three genes related to kojic acid production in this strain were transcribed in higher amounts than those found in the wild-type strain. This strain produced 26.4 g/L kojic acid from 80 g/L glucose. Furthermore, this strain was transformed with plasmid harboring 3 cellulase genes. The resultant A. oryzae strain successfully produced 0.18 g/L of kojic acid in 6 days of fermentation from the phosphoric acid swollen cellulose.
  
  
  CONCLUSIONS
  Kojic acid was produced directly from cellulose material using genetically engineered A. oryzae. Because A. oryzae has efficient protein secretion ability and secondary metabolite productivity, an A. oryzae-based cell factory could be a platform for the production of various kinds of bio-based chemicals.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Yamada
authors.forename: Toshihide
authors.initials: T
authors.lastname: Yoshie
authors.forename: Satoshi
authors.initials: S
authors.lastname: Wakai
authors.forename: Nanami
authors.initials: N
authors.lastname: Asai-Nakashima
authors.forename: Fumiyoshi
authors.initials: F
authors.lastname: Okazaki
authors.forename: Chiaki
authors.initials: C
authors.lastname: Ogino
authors.forename: Hiromoto
authors.initials: H
authors.lastname: Hisada
authors.forename: Hiroko
authors.initials: H
authors.lastname: Tsutsumi
authors.forename: Yoji
authors.initials: Y
authors.lastname: Hata
authors.affiliation: Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodaicho, Nada-ku, Kobe, Hyogo 657-8501, Japan. akondo@kobe-u.ac.jp.
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D001236:Aspergillus oryzae / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D061249:Batch Cell Culture Techniques; D002480:Cellulase / Q000235:genetics / Q000378:metabolism; D002482:Cellulose / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D010957:Plasmids / Q000235:genetics / Q000378:metabolism; D011753:Pyrones / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005656:Fungal Proteins; D011753:Pyrones; C011890:kojic acid; D002482:Cellulose; D002480:Cellulase; D005947:Glucose