Abstract:

Engineering strain was acquired by transforming directly evolved plasmid from the incubated conservation bacterium E. coli BL21（DE3）pLysS/PET-15b-dhaT’-24 to the host cell E. coli BL21（DE3）pLysS. The lactose induced engineering strain was fermented to acquire 1,3-propanediol oxidoreductase（PDOR）with 182 U/mL activity. The optimal reaction pH was 10 and the pH stabile range was 7.0—9.0. The optimal reaction temperature was 55 ℃ and stabile temperature range was 30—45 ℃. 3-Hydroxypropionaldehyde（3-HPA）was catalysed by the PDOR to produce 1,3-propanediol（1,3-PD）. The reaction was coupled with another reaction of glycerol dehydrogenase（GDH，acquired from another engineering strain）to realize NADH regeneration. Thus，1,3-PD coupling enzymatic catalysis was constructed. Due to the two enzymes from engineering strains showed suitable characteristics，the reaction was continued for 34 hours and 63.4% translation rate of 3-HPA，64.6% 1,3-PD production rate were acquired.