초록
<P>L‐Ser is often used to synthesize some significant <SMALL>l</SMALL>‐noncanonical α‐amino acids(<SMALL>l</SMALL>‐ncAAs), which are the prevalent intermediates and precursors for functional synthetic compounds. In this study, threonine aldolase from <I>Escherichia coli</I> k‐12 MG1655 has been used to synthesize <SMALL>l</SMALL>‐Ser. In contrast to the maximum catalytic capacity (20 g/L) for <SMALL>l</SMALL>‐threonine aldolase(LTA), <SMALL>d</SMALL>‐Ser was synthesized with high yield (240 g/L) from cheap Gly and paraformaldehyde using <SMALL>d</SMALL>‐threonine aldolase (DTA) from <I>Arthrobacter sp</I> ATCC. In order to fully utilize <SMALL>d</SMALL>‐Ser and expand the resource of <SMALL>l</SMALL>‐Ser, a dynamic kinetic resolution system was constructed to convert <SMALL>d</SMALL>/<SMALL>dl</SMALL>‐Ser to <SMALL>l</SMALL>‐Ser through combining alanine racemase (Alr) from <I>Bacillus subtilis</I> with <SMALL>l</SMALL>‐tryptophan synthase (TrpS) from <I>Escherichia coli</I> k‐12 MG1655, and <SMALL>l</SMALL>‐ncAAs including <SMALL>l</SMALL>‐Trp and <SMALL>l</SMALL>‐Cys derivatives were synthesized with excellent enantioselectivity and in high yields. The results indicated <SMALL>l</SMALL>‐ncAAs could be efficiently synthesized from <SMALL>d</SMALL>‐Ser using this original and green dynamic kinetic resolution system, and the reliable <SMALL>l</SMALL>‐Ser resource has been established from simple and achiral substrates.</P>