Tryptophanase gene deficiency improves the application of dioxygenase to 3-(2-hydroxyethyl)catechol production

Megumi Matsude, Himeka Okamoto, Riku Aono, Kuniki Kino*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


3-(2-Hydroxyethyl)catechol (HEC) is a polyphenol reported to exhibit skin-lightning and antioxidative effects, and hence is expected to be used as cosmetic and food additives and chemical products such as electronic materials. In this study, we established biocatalytic HEC production from 2-phenylethanol using the dioxygenase whose expression was induced by toluene, CumA, and its flanking dehydrogenase, CumB, from an isolated strain, Pseudomonas sp. K17. Escherichia coli cells coexpressing CumA and CumB were stained blue during cultivation in Luria–Bertani medium, and HEC was not produced upon using the cell-free extracts as biocatalysts, likely resulting from the inhibitory effects of the blue dyes. The disruption of the tryptophanase gene of E. coli was found to repress the generation of the blue dyes, and enhanced HEC production. The blue dyes were extracted from the cell-free extracts, and their molecular formula was C16H10N2O3, suggesting they were monooxygenated indigo or its isomers. Although repression of blue dye formation and enhancement of HEC production were observed when cells were cultivated with glucose, the percent yield of HEC was 84% at 20 h, whereas that with tryptophanase disruption strain was 84% at 4 h. It was suggested that tryptophanase gene disruption could contribute to more efficient HEC production.

Original languageEnglish
Pages (from-to)241-246
Number of pages6
JournalJournal of Bioscience and Bioengineering
Issue number3
Publication statusPublished - 2021 Sept


  • 3-(2-Hydroxyethyl)catechol
  • Dehydrogenase
  • Dioxygenase
  • Gene disruption
  • Tryptophanase

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology


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