(191s) A Platform for Biosynthesis of D-Amino Acids

D-amino acids (DAAs) have broad applications in pharmaceutical, insecticide and food. Two current methods in DAAs manufacturing—asymmetric chemical synthesis and enzymatic transformation—are costly due to expensive input and complicated process. Fermentation could be a potential green and low-cost process for DAAs manufacturing. Herein, we introduce a broad substrate specificity D-amino acid-N-acetyltransferase and construct a two-step platform method for DAAs biosynthesis: 1) Racemization from LAAs to DAAs; 2) N-acetyltransfer of DAAs to N-acetyl-DAAs. This N-acetyltransfer reaction could protect cells from DAAs toxicity and drive the racemization to DAAs. To demonstrate this platform, we use D-serine as an example and achieve a yield 44% of the theoretical maximum from L-serine. This method could be expanded to other D-amino acids with protein engineering and fermentation optimization.