[P002] Poster

1:00 PM - 1:50 PM JST(4:00 AM - 4:50 AM UTC)

[P01-010] Bio-based Production of Porphyrins and Their Derivatives Using Engineered Corynebacterium glutamicum for Photoactive and Antioxidant Applications

Byeong-Hyeon Cho¹, Myeong-Eun Lee¹, Joonhee Chang¹, ○Sung Ok Han¹ (1. Korea University (Korea))

Keywords:

Porphyrins,Biosynthesis,Corynebacterium glutamicum,Photoactive,antioxidant

Porphyrins are tetrapyrrolic macrocycles composed of four pyrrole units interconnected by methine bridges. Their derivatives, including bilirubin and phycocyanobilin, are linear tetrapyrroles that originate from the cleavage of the porphyrin ring structure. Porphyrins and their derivatives play essential roles in numerous biological processes, including oxygen transport, photosynthesis, and enzymatic catalysis. Corynebacterium glutamicum, a microorganism designated as Generally Recognized As Safe (GRAS), was metabolically engineered to enhance the porphyrin and its derivative biosynthetic pathways. By increasing the supply of the key precursor aminolevulinic acid (ALA), together with downstream pathway optimization, cofactor supplementation, and membrane engineering, the production of various porphyrins and their derivatives was significantly improved. Due to their extensive π-electron conjugation and strong metal-chelating properties, porphyrins exhibit unique physicochemical characteristics, including UV–visible light absorption, antimicrobial activity, and antioxidant activity. Zn-porphyrins demonstrated up to a 6.1-fold enhancement in photoprotective performance. When combined with lignin derived from lignocellulosic biomass, the resulting bio-based Zn-porphyrin sunscreen exhibited broad-spectrum UV shielding, high sun protection factor (SPF) values, and strong radical-scavenging activity. In addition, Zn-porphyrins showed antibacterial activity mediated by photoinduced reactive oxygen species (ROS) generation. Immobilization of Zn-porphyrins onto a cellulose membrane produced a versatile antibacterial material, achieving more than 90% antibacterial efficiency under light irradiation. Porphyrin-derived compounds, bilirubin and phycocyanobilin, were produced from glucose in flask cultures, reaching titers of 22.43 mg/L and 259.63 mg/L, respectively, and exhibited antioxidant activities of up to 76.33% and 88%, comparable to those of the standard compounds. Overall, the production of porphyrins and their derivatives in C. glutamicum represents a promising and sustainable strategy for producing high-value porphyrin-based bio-materials with diverse industrial applications, owing to their useful functionalities such as photosensitizing and antioxidant activities.