Enhanced production of d‐()‐3‐hydroxybutyric acid by recombinant Escherichia coli

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摘要：

Wild-type bacteria including Escherichia coli normally do not produce extracellular D-()-3-hydroxybutyric acid (3HB). To produce extracellular chiral 3HB, a new pathway for synthesis of 3HB was constructed by simultaneous expression of genes of β-ketothiolase ( phbA), acetoacetyl-CoA reductase ( phbB), phosphor-transbutyrylase ( ptb) and butyrate kinase ( buk) in E. coli strain DH5α. E. coli DH5α containing any one of the four plasmids pBHR69, pUCAB, p68CM or pKKAB that harbor the phbA and phbB genes produced small amounts of 3HB, ranging from 75 to 400 mg l 1, while E. coli DH5α harboring p68CMPTK containing genes of phbA, phbB, ptb and buk increased the 3HB concentration to 1.4 g l 1 in shake flasks supplemented with LB broth and 20 g l 1 glucose. 3HB production was further improved to over 2 g l 1 in shake flasks when E. coli DH5α hosted two plasmids simultaneously that separately contained phbA and phbB in one plasmid while ptb and buk in the other. A batch fermentation run in a 5-l fermenter produced approximately 5 g l 1 3HB after 24 h. A fed-batch process increased 3HB production to 12 g l 1 after 48 h of fermentation.

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关键词：

Polyhydroxyalkanoate Poly-d-(−)-3-hydroxybutyric acid d-(−)-3-Hydroxybutyric acid Escherichia coli

DOI：

10.1016/S0378-1097(02)00788-7

被引量：

189

年份：

2002