Niu Wei, Guo Jiantao
Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States.
ACS Synth Biol. 2015 Apr 17;4(4):378-82. doi: 10.1021/sb500240p. Epub 2014 Jul 9.
Biocatalytic syntheses are increasingly explored as the alternate platform of chemical production in order to address the sustainable development challenge faced by the current chemical industry. Here, we report the design and implementation of an artificial pathway to convert lactic acid into 1,2-propanediol. It circumvents a highly cytotoxic intermediate that exists in a widely used natural pathway. We identified and characterized a key enzyme that catalyzed the nonnatural step of the pathway. After 72 h of cultivation under shake-flask conditions, an Escherichia coli biocatalyst expressing the artificial route synthesized 1.5 g/L of R- or 1.7 g/L of S-1,2-propanediol from D- or L- lactic acid at high enantiomeric purity, respectively. The bioconversion is part of a novel biosynthetic pathway that can be further incorporated into appropriate microbial hosts for the de novo synthesis of optically pure 1,2-propanediol from renewable feedstocks.
为应对当前化学工业面临的可持续发展挑战，生物催化合成作为化学生产的替代平台正得到越来越多的探索。在此，我们报告了一条将乳酸转化为1,2-丙二醇的人工途径的设计与实施。它规避了一条广泛使用的天然途径中存在的一种高细胞毒性中间体。我们鉴定并表征了一种催化该途径非天然步骤的关键酶。在摇瓶条件下培养72小时后，表达该人工途径的大肠杆菌生物催化剂分别从D-或L-乳酸中合成了1.5 g/L的R-或1.7 g/L的S-1,2-丙二醇，对映体纯度很高。该生物转化是一条新型生物合成途径的一部分，可进一步整合到合适的微生物宿主中，以从可再生原料从头合成光学纯的1,2-丙二醇。
