1,6-Hexanediamine is an important monomer for polyamide materials such as nylon 66, and the development of a biosynthetic route that is independently controllable, mild, and sustainable is of great significance.In this study, a cell-free catalytic system composed of carboxylic acid reductase and transaminase was constructed to improve the efficiency of 1,6-hexanediamine production from adipic acid.The efficiency of cascade flux transfer was enhanced through screening of key enzyme combinations and process intensification.The results showed that the titer of 1,6-hexanediamine reached 36.5 mg/L in the purified enzyme catalytic system.After the introduction of the cell-free catalytic system, the kinetic matching of the cascade reaction was improved and intermediate accumulation was alleviated, resulting in an increase in the titer of 1,6-hexanediamine to 329.7 mg/L.After further optimization of the reaction process, the maximum titer of 1,6-hexanediamine reached 571.8 mg/L at 9 h.These results lay a foundation for the green biomanufacturing of 1,6-hexanediamine and the process intensification of cell-free systems, and provide technical support for the further development of related biomanufacturing processes.
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