Engineering a Hybrid Heme Pathway for Hemoprotein‐Based Dye‐Decolorizing Peroxidase in Escherichia coli

Journal article

Dye‐decolorizing peroxidases (DyPs) are heme‐dependent oxidoreductases with promising applications in mycotoxin detoxification by acting on the oxidizable conjugated structures of aflatoxin B1 (AFB1). The heme prosthetic group is critical for the catalytic process by mediating electron transfer and intermediate formation that govern overall enzymatic activity. However, intracellular heme biosynthesis in microbial hosts is tightly regulated, frequently leading to suboptimal catalytic performance of recombinant DyPs, thus highlighting the necessity to improve cofactor availability. To establish an efficient heme‐based expression system for DyPs, we developed a heme cofactor supplementation system in Escherichia coli by introducing a heterologous C4 pathway harboring 5‐aminolevulinic acid synthase from Caulobacter segnis together with the outer membrane heme transporter ChuA. Furthermore, intracellular heme supply was optimized by the integrated overexpression of the C4 and C5 pathways as well as the hemEFGH gene cluster, which significantly enhanced RhDypB‐R80 activity. The engineered cells exhibited substantially higher heme content and RhDypB‐R80 activity compared to those produced by conventional cultivation methods supplemented with exogenous 5‐ALA. Notably, heme‐based RhDypB‐R80 achieved 91.03% AFB1 degradation within 24 h, demonstrating its potential for enzymatic detoxification applications. This engineered heme‐producing host provides a practical platform for enhancing hemoprotein activity and supports the development of enzymatic strategies for mycotoxin control in food systems.

Authors: Sun, Y; Chen, J; Wang, N; Su, C; Li, H

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Wiley
• Journal: Food Bioengineering
• Article number: fbe2.70063
• Publication date: 2026-06-03
• Acceptance date: 2026-05-22
• DOI: 10.1002/fbe2.70063
• EISSN: 2770-2081
• ISSN: 2770-2081
• Language: English
• Keywords: Escherichia coli; dye‐decolorizing peroxidase; heme biosynthesis; aflatoxin B1 degradation; hemoprotein engineering