• Sangkyu Park, Kiyoon Kang, Shin Woo Lee, Mi-Jeong Ahn, Jung-Myung Bae & Kyoungwhan Back (2010). Production of serotonin by dual expression of tryptophan decarboxylase and tryptamine 5-hydroxylase in Escherichia coli. Applied Microbiology and Biotechnology.
  • PARK Munyoung, KANG Kiyoon, PARK Sangkyu & BACK Kyoungwhan (2014). Conversion of 5-Hydroxytryptophan into Serotonin by Tryptophan Decarboxylase in Plants, Escherichia coli, and Yeast. Bioscience, Biotechnology, and Biochemistry.
  • José-Aníbal Mora-Villalobos & An-Ping Zeng (2018). Synthetic pathways and processes for effective production of 5-hydroxytryptophan and serotonin from glucose in Escherichia coli. Journal of Biological Engineering.