Efficient biosynthesis of enantiopure tolvaptan by utilizing alcohol dehydrogenase-catalyzed enantioselective reduction

2018 ◽  
Vol 20 (6) ◽  
pp. 1224-1227 ◽  
Author(s):  
Hong-Lei Zhang ◽  
Chao Zhang ◽  
Meng-Nan Han ◽  
Chao-Hong Pei ◽  
Zhi-Dong Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Alcohol Dehydrogenase ◽  
Soybean Oil ◽  
Efficient Method ◽  
Formate Dehydrogenase ◽  
Whole Cells ◽  
Enantioselective Reduction

Using whole cells of Escherichia coli co-expressing alcohol dehydrogenase (PsADH) and formate dehydrogenase (CpFDH) in a biphasic aqueous–soybean oil system is shown to be an efficient method for the biosynthesis of enantiopure tolvaptan.

scholarly journals Promising Pathway of Thermostable Mannitol Dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108 for D-Mannitol Synthesis

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 76
Author(s):  
Marwa Y. F. Koko ◽  
Rokayya Sami ◽  
Bertrand Muhoza ◽  
Ebtihal Khojah ◽  
Ahmed M. A. Mansour
Keyword(s):  
Escherichia Coli ◽  
Formate Dehydrogenase ◽  
Enzyme System ◽  
Catalytic Efficiency ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Mannitol Dehydrogenase ◽  
Whole Cells ◽  
Optimum Ph ◽  
Molecular Masses

In this study, we conducted the characterization and purification of the thermostable mannitol dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108. Furthermore, a coupling-enzyme system was designed using (MtDH) from Caldicellulosiruptor hydrothermalis 108 and formate dehydrogenase (FDH) from Ogataea parapolymorpha. The biotransformation system was constructed using Escherichia coli whole cells. The purified enzyme native and subunit molecular masses were 76.7 and 38 kDa, respectively, demonstrating that the enzyme was a dimer. The purified and couple enzyme system results were as follows; the optimum pH for the reduction and the oxidation was 7.0 and 8.0, the optimum temperature was 60 °C, the enzyme activity was inhibited by EDTA and restored by zinc. Additionally, no activity was detected with NADPH and NADP. The purified enzyme showed high catalytic efficiency Kcat 385 s−1, Km 31.8 mM, and kcat/Km 12.1 mM−1 s−1 for D-fructose reduction. Moreover, the purified enzyme retained 80%, 75%, 60%, and 10% of its initial activity after 4 h at 55, 60, 65, and 75 °C, respectively. D-mannitol yield was achieved via HPLC. Escherichia coli are the efficient biotransformation mediator to produce D-mannitol (byproducts free) at high temperature and staple pH, resulting in a significant D-mannitol conversation (41 mg/mL) from 5% D-fructose.

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