High concentration synthesis of 3-hydroxypropionic acid

Enzymatic synthesis of 3-hydroxypropionic acid at high productivity by using free or immobilized cells of recombinant Escherichia coli

 Shanshan Yua, Peiyuan Yao, Jianjiong Li, Jie Ren, Jing Yuan, Jinhui Feng, Min Wang, Qiaqing Wu,  Dunming Zhu,

Journal of Molecular Catalysis B: Enzymatic, Volume 129, July 2016, Pages 37-42

doi:10.1016/j.molcatb.2016.03.011

3-Hydroxypropionic acid (3-HP) is an important platform chemical for organic synthesis and high performance polymers. This paper describes an effective enzymatic method for the synthesis of 3-HP was achieved by using free or immobilized recombinant Escherichia coli BL21(DE3) cells harboring a nitrilase gene from environmental sample (NIT190). Under the optimal conditions (100 mmol/L Tris-HCl buffer, pH 8.0, 30 °C), the maximum substrate concentration which led to 100% hydrolysis by using free cells within 24 h was 4.5 mol/L (319.5 g/L). Furthermore, immobilization of the whole cells enhanced their substrate tolerance (up to 7.0 mol/L), stability, and reusability. The immobilized cells could be reused for up to 30 batches, and 70% of enzyme activity was retained after 74 batches in distilled water. A productivity (36.9 g/(L h)) was obtained after isolation and purification of 3-HP from the first 30 batches.

Figure shows free cell substrate tolerance (a) compared to three immobilized cell methods (b-d).