Exploring the effects of carbon sources on the metabolic capacity for shikimic acid production in Escherichia coli using in silico metabolic predictions.
Effects of various industrially important carbon sources (glucose, sucrose, xylose, gluconate, and glycerol) on shikimic acid (SA) biosynthesis in Escherichia coli were investigated to gain new insight into the metabolic capability for overproducing SA. At the outset, constraints-based flux analysis using the genome-scale in silico model of E. coli was conducted to quantify the theoretical maximum SA yield. The corresponding flux distributions fueled by different carbon sources under investigation were compared with respect to theoretical yield and energy utilization, thereby identifying the indispensable pathways for achieving optimal SA production on each carbon source. Subsequently, a shikimate-kinase-deficient E. coli mutant was developed by blocking the aromatic amino acid pathway, and the production of SA on various carbon sources was experimentally examined during 5 l batch culture. As a result, the highest production rate, 1.92 mmol SA/h, was obtained when glucose was utilized as a carbon source, whereas the efficient SA production from glycerol was obtained with the highest yield, 0.21 mol SA formed per mol carbon atom of carbon source consumed. The current strain can be further improved to satisfy the theoretically achievable SA production that was predicted by in silico analysis.
Ahn
Jung Oh
JO
Division of Biotechnology R&BD, Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-333, Korea.
Lee
Hong Weon
HW
Saha
Rajib
R
Park
Myong Soo
MS
Jung
Joon-Ki
JK
Lee
Dong-Yup
DY
D001709:Biotechnology / Q000379:methods*; D002244:Carbon / Q000737:chemistry / Q000378:metabolism*; D003470:Culture Media; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D016680:Genome, Bacterial; D008954:Models, Biological; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism; D012765:Shikimic Acid / Q000378:metabolism*
D003470:Culture Media; D012765:Shikimic Acid; D002244:Carbon; D017853:Phosphotransferases (Alcohol Group Acceptor); C022642:shikimate kinase