Cadaverine Production by Using Cross-Linked Enzyme Aggregate of Escherichia coli Lysine Decarboxylase

Lysine decarboxylase (CadA) converts L-lysine into cadaverine (1,5-pentanediamine), which is an important platform chemical with many industrial applications. Although there have been many efforts to produce cadaverine through the soluble CadA enzyme or Escherichia coli whole cells overexpressing the CadA enzyme, there have been few reports concerning the immobilization of the CadA enzyme. Here, we have prepared a cross-linked enzyme aggregate (CLEA) of E. coli CadA and performed bioconversion using CadACLEA. CadAfree and CadACLEA were characterized for their enzymatic properties. The optimum temperatures of CadAfree and CadACLEA were 60°C and 55°C, respectively. The thermostability of CadACLEA was significantly higher than that of CadAfree. The optimum pH of both enzymes was 6.0. CadAfree could not be recovered after use, whereas CadACLEA was rapidly recovered and the residual activity was 53% after the 10th recycle. These results demonstrate that CadACLEA can be used as a potential catalyst for efficient production of cadaverine.