Nijkamp Karin, Westerhof R G Maaike, Ballerstedt Hendrik, de Bont Jan A M, Wery Jan
Business Unit, Food and Biotechnology Innovations, TNO Quality of Life, P.O. Box 342, 7300 AH, Apeldoorn, The Netherlands.
Appl Microbiol Biotechnol. 2007 Mar;74(3):617-24. doi: 10.1007/s00253-006-0703-0. Epub 2006 Nov 17.
A Pseudomonas putida S12 strain was constructed that is able to convert glucose to p-coumarate via the central metabolite L: -tyrosine. Efficient production was hampered by product degradation, limited cellular L: -tyrosine availability, and formation of the by-product cinnamate via L: -phenylalanine. The production host was optimized by inactivation of fcs, the gene encoding the first enzyme in the p-coumarate degradation pathway in P. putida, followed by construction of a phenylalanine-auxotrophic mutant. These steps resulted in a P. putida S12 strain that showed dramatically enhanced production characteristics with controlled L: -phenylalanine feeding. During fed-batch cultivation, 10 mM (1.7 g l(-1)) of p-coumarate was produced from glucose with a yield of 3.8 Cmol% and a molar ratio of p-coumarate to cinnamate of 85:1.
构建了一种恶臭假单胞菌S12菌株，该菌株能够通过中心代谢物L-酪氨酸将葡萄糖转化为对香豆酸。产品降解、细胞内L-酪氨酸可用性有限以及通过L-苯丙氨酸形成副产物肉桂酸阻碍了高效生产。通过使恶臭假单胞菌中对香豆酸降解途径中的第一种酶的编码基因fcs失活，随后构建苯丙氨酸营养缺陷型突变体，对生产宿主进行了优化。这些步骤产生了一种恶臭假单胞菌S12菌株，该菌株在控制L-苯丙氨酸补料的情况下表现出显著增强的生产特性。在分批补料培养过程中，从葡萄糖中产生了10 mM（1.7 g l(-1)）的对香豆酸，产率为3.8 Cmol%，对香豆酸与肉桂酸的摩尔比为85:1。
