Mechanistic Insights into Indigo Reduction in Indigo Fermentation: A Voltammetric Study

• NAKAGAWA Kasumi

  Graduate School of Advanced Technology and Science, Tokushima University

• TAKEUCHI Michiki

  Industrial Microbiology, Graduate School of Agriculture, Kyoto University

• KIKUCHI Mayu

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• KIYOFUJI Suzuna

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• KUGO Masami

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• SAKAMOTO Takaiku

  Graduate School of Advanced Technology and Science, Tokushima University Graduate School of Technology, Industrial and Social Sciences, Tokushima University

• KANO Kenji

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• OGAWA Jun

  Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University

• SAKURADANI Eiji

  Graduate School of Advanced Technology and Science, Tokushima University Graduate School of Technology, Industrial and Social Sciences, Tokushima University

Abstract

Indigo is one of the oldest natural blue dyes. Microorganisms and their enzymatic activities are deeply involved in the traditional indigo staining procedure. To elucidate the mechanism of the microbial indigo reduction, we directly performed cyclic voltammetry on alkaline fermenting dye suspensions. A pair of characteristic redox peaks of leuco-indigo was observed in a supernatant fluid of the fermenting dye suspension. On the other hand, it was found that the indigo/leuco-indigo redox couple mediated two-way microbially catalyzed oxidation and reduction in a sediment-rich suspension of the fermenting suspension. Acetaldehyde was supposed to be the electron donor and acceptor of the catalytic reactions. In order to verify the bioelectrocatalytic reaction, we isolated indigo-reducing bacterium K2-3′ from the fermenting suspension, and the two-way bioelectrocatalysis was successfully restaged in a model system containing K2-3′ and methyl viologen (as a soluble mediator instead of indigo) as well as acetaldehyde at pH 10.

Journal

• Electrochemistry

  Electrochemistry 89 (1), 25-30, 2021-01-05

  The Electrochemical Society of Japan

Keywords

• Indigo Reduction Mechanism
• Acetaldehyde
• Bioelectrocatalysis
• Mediator

Details

• CRID: 1390568456342112896
• NII Article ID: 130007965922
• DOI: 10.5796/electrochemistry.20-00123
• ISSN: 21862451
• ISSN: 13443542
• Web Site: http://repo.lib.tokushima-u.ac.jp/116295
• Web Site: https://www.jstage.jst.go.jp/article/electrochemistry/89/1/89_20-00123/_pdf
• Text Lang: en
• Data Source:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles
  • KAKEN
• Abstract License Flag: Allowed