Khobragade_2021_Biotechnol.Bioeng__

Here, we report a bienzymatic cascade to produce beta-amino acids as an intermediate for the synthesis of the leading oral antidiabetic drug, sitagliptin. A whole-cell biotransformation using recombinant E. coli co-expressing a esterase and transaminase were developed, wherein the desired expression level of each enzyme was achieved by promotor engineering. The small-scale reactions (30 mL) performed under optimized conditions at varying amounts of substrate (100-300 mM) resulted in excellent conversions of 82-95% for the desired product. Finally, a kilogram-scale enzymatic reaction (250 mM substrate, 220 L) was carried out to produce beta-amino acid (229 mM). Sitagliptin phosphate was chemically synthesized from beta-amino acids with 82% yield and > 99% purity. This article is protected by copyright. All rights reserved.