Renewable Vanillylamine Synthesis from Lignin-Derived Feedstocks

Lignin is considered one of the most abundant renewable resources on earth. In this study, we developed an efficient Escherichia coli -based whole-cell biocatalytic approach for the synthesis of vanillylamine from two lignin-derived substrates (ferulic acid and vanillic acid). For the synthesis of vanillylamine from ferulic acid, we used recombinant E. coli expressing feruloyl-CoA synthetase and enoyl-CoA hydratase/aldolase from Pseudomonas putida, ω-transaminase (CvTA) from Chromobacterium violaceum, and l -alanine dehydrogenase (AlaDH) from Bacillus subtilis . At the appropriate NH 4 Cl concentration, 20 mM ferulic acid afforded 19.22 mM vanillylamine, with a conversion rate reaching 96.1%. For the synthesis of vanillylamine from vanillic acid, we used recombinant E. coli expressing carboxylic acid reductase from Segniliparus rotundus, CvTA from C. violaceum and AlaDH from B. subtilis . Under the optimal condition, 18.9 mM vanillylamine was obtained from 20 mM vanillic acid, with a conversion rate of 94.5%. Taken together, our work represents one of the pioneering studies in the development of E. coli -based whole-cell biocatalysts for the eco-friendly synthesis of vanillylamine from lignin-derived feedstocks.