Engineering a hybrid system of Corynebacterium glutamicum and co-immobilized enzymes for efficient cadaverine production from glycerol

Abstract

1,5-Diaminopentane (cadaverine) is a critical raw material for producing bio-based polyamides. With growing concerns about the depletion of fossil resources and the increasing demand for sustainable industrial solutions, the biosynthesis of cadaverine has attracted significant attention. Currently, the de novo biosynthesis of cadaverine primarily uses glucose as the substrate, but high costs undermine its competitive advantage against other biomaterials, requiring novel production routes. Here, a cell factory coupled with co-immobilized enzymes was employed to produce cadaverine using glycerol as the sole carbon source. Corynebacterium glutamicum was first engineered to produce lysine from glycerol. Subsequently, the initial strain CGgly2 was engineered by regulating the lysine biosynthetic pathway and enhancing the reducing power supply pathway. The lysine yield of recombinant strain LYS10 reached 19.0 g L⁻¹ in shake flask cultures after optimizing fermentation parameters. For efficient bioconversion of cadaverine, an “EKylation” strategy was employed to engineer lysine decarboxylase. Besides, the engineered enzyme was co-immobilized with pyridoxal 5′-phosphate (PLP) using epoxy resin, resulting in the enzyme complex ER604-10EK-PLP, which exhibited significantly enhanced catalytic activity and stability. Ultimately, strain LYS10 was combined with complex ER604-10EK-PLP in a 5 L fermenter, and 90.7 g L⁻¹ cadaverine was accumulated via fed-batch fermentation with a yield of 0.2 g g⁻¹ glycerol, which was the highest titer of cadaverine reported from glycerol. This hybrid platform is promising for sustainable production of cadaverine, offering a viable alternative to fossil-derived chemicals.