Effect of ribose, xylose, aspartic acid, glutamine and nicotinic acid on ethyl (S)-4-chloro-3-hydroxybutanoate synthesis by recombinant Escherichia coli
2012
Li, Nan | Zhang, Yueyuan | Ye, Qi | Zhang, Yuzhe | Chen, Yong | Chen, Xiaochun | Wu, Jinglan | Bai, Jianxin | Xie, Jingjing | Ying, Hanjie
Most reductases which belong to the short chain dehydrogenase/reductase (SDR) superfamily require NAD (P) H for activity. Addition of this cofactor was still necessary for the production of ethyl (S)-4-chloro-3-hydroxybutanoate by Escherichia coli even when a cofactor regeneration system was constructed by co-expressing carbonyl reductase from Pichia stipitis (PsCRI) and glucose dehydrogenase from Bacillus megaterium (BmGDH). In an attempt to reduce dependence on the expensive cofactor, compounds directly or indirectly involved in NADP synthesis were added to the medium. Only glutamine and xylose enhanced the content of intracellular NADP (H) and the concentration of product. The concentration and yield of (S)-CHBE reached 730mM and 48.7%, with 30g/L of glutamine and 40g/L of xylose, a 2.6-fold increase over the control without the addition of the two compounds.
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