Strengthening NADPH Regeneration for Improving Photo-biocatalytic Ketones Asymmetric Reduction Reaction by Synechocystis Through Overexpression of FNR
Microalgae are excellent biocatalyst candidates for photo-biocatalytic-asymmetric reduction of prochiral ketones to produce enantiomer alcohols. In the biocatalysis asymmetric reduction of carbonyl group process, the cofactor, NADPH, plays a key role. So the current study focused on the effect of NADPH availability on the reduction. Photosynthesis is a main pathway for NADPH regeneration in microalgae, and the ferredoxin-NADP+ oxidoreductase (FNR) is the key enzyme in this process. In this work, we constructed an engineered cyanobacterium Synechocystis sp. PCC6803::Ω-PpetE-petH to overexpress FNR gene petH to strengthen NADPH regeneration. The results show that the intracellular NADPH content was increased 80.8% compared to the wild type. Applying the Synechocystis sp. PCC6803::Ω-PpetE-petH to catalyze the model asymmetric reduction reaction (reduction of acetophenone to S-phenylethanol), the yield was improved 61.2% compared to the wild-type. This work makes the microalgal biocatalysis asymmetric reduction process become more preponderant via providing a new route to enhance the regeneration of cofactor NADPH.
Putative metabolic process of nicotinamide adenine dinucleotide phosphate (NADPH) regeneration and the photo-biocatalytic-asymmetric reduction reaction of prochiral ketones in microalgal cells.
KeywordsBiocatalyst Synechocystis sp. PCC6803 FNR NADPH Asymmetric reduction
The present work was financed by the National Natural Science Foundation of China (Grant No. 21376184), the Scientific Research Foundation for the Returned Overseas Chinese Scholars (State Education Ministry), Foundation from Educational Commission of Hubei Province of China (Grant No. D20121108), the Ministry of Science and Technology of China (2017YFF0205803), and the National Institute of Metrology of China (21-AKY1615), and Science and Technology Innovation Special Major Project of Hubei Province (No. 2017ACA179).
- 11.Wang Y, San KY, Bennett GN (2013) Curr Opin Biotechnol 24:994–999Google Scholar
- 13.Li H-D, Sun Z-H, Ni Y (2013) Chem Res Chin Univ 29:1140–1148Google Scholar
- 22.Thor JV, Hellingwerf KJ, Matthijs HCP (1998) Plant Mol Biol 36:353–363Google Scholar
- 23.Gao H, Tang Q, Xu X-D (2007) Acta Hydrobiol Sin 31:240–244Google Scholar
- 26.Williams J (1998) Methods Enzymol 167:766–778Google Scholar
- 28.Zhang L, Mcspadden B, Pakrasi HB, Whitmarsh J (1992) J Biol Chem 267:19054–19059Google Scholar