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

Abstract

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 <i>Escherichia coli</i> 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 <i>E. coli</i> CadA and performed bioconversion using CadA^CLEA. CadA^free and CadA^CLEA were characterized for their enzymatic properties. The optimum temperatures of CadA^free and CadA^CLEA were 60°C and 55°C, respectively. The thermostability of CadA^CLEA was significantly higher than that of CadA^free. The optimum pH of both enzymes was 6.0. CadA^free could not be recovered after use, whereas CadA^CLEA was rapidly recovered and the residual activity was 53% after the 10^th recycle. These results demonstrate that CadA^CLEA can be used as a potential catalyst for efficient production of cadaverine.