Zero-valent iron driven bioconversion of glycerol to 1,3-propanediol using Klebsiella pneumoniae L17

Abstract 1,3-PDO (1,3-propanediol) is a high value-added platform chemical used widely in adhesives, laminates, and food additives. For the efficient production of 1,3-PDO, the sustainable and non-toxic regeneration of NADH is of great importance. ZVI (Zero-Valent Iron) can provide a reducing equivalent for 1,3-PDO synthesis from glycerol as an electron donor. Klebsiella pneumoniae has a 1,3-PDO conversion pathway from glycerol and has been studied as an electrochemically active strain that can exchange respiratory electrons through the cell membrane. In this study, 1,3-PDO was produced using an electrochemically active strain, K. pneumoniae L17, and ZVI as an electron donor. The production of 1,3-PDO with ZVI increased significantly to 24.2 ± 1.3 mM compared to the control (12.0 ± 0.1 mM). These results suggest that an external reducing agent, such as ZVI, can regulate the bioconversion of K. pneumoniae L17, and improve the conversion of glycerol to value-added platform chemicals.