Engineered Vibrio natriegens with a Toxin–Antitoxin System for High-Productivity Biotransformation of l-Lysine to Cadaverine

Abstract

Vibrio natriegens, a fast-growing bacterium, is an emerging chassis of next-generation industrial biotechnology capable of thriving under open and continuous culture conditions. Cadaverine, a valuable industrial C5 platform chemical, has various chemical and biological activities. This study found that V. natriegens exhibited superior tolerance to lysine, the substrate of cadaverine production. For the first time, a cadaverine synthesis pathway was introduced into V. natriegens for whole-cell catalysis of cadaverine from lysine. A high-efficiency cadaverine-producing strain harboring a toxin–antitoxin system, V. natriegens (pSEVA341-pTac-ldcC-pHbpBC-hbpBC) with lysE (PN96_RS17440) inactivation, was constructed. In 7 L bioreactors, the cadaverine titer increased from 115 g/L in the original strain to 158 g/L within 11 h of biotransformation, exhibiting a 37% increase in production. Its productivity reached 14.4 g/L/h with a conversion rate as high as 90%. These results confirm V. natriegens as an exceptional chassis for effective cadaverine bioproduction.