Characterization of D-xylose isomerase from Shinella zoogloeoides NN6 and its application for producing D-allulose and two D-ketopentoses in a one-pot multi-step transformation

[摘要] Researchers continue to search for efficient processes to reduce the production costs of rare sugars.In this paper, we report a novel d-xylose isomerasefrom Shinella zoogloeoides NN6 (SzXI) and itsapplication for efficient rare sugar production. Purified SzXI did not show remarkable properties whencompared with those of a previously reportedd-xylose isomerase. However, NN6 was found toexpress inducible SzXI and constitutive d-allulose3-epimerase (SzAE) when cultivated with d-xyloseas the sole carbon source. These two enzymes werepartially purified and immobilized onto HPA25L,an anion exchange resin. The co-immobilized SzXIand SzAE (i-XA) showed optimal activity at 65°Cin sodium phosphate buffer (pH 7.5) and 90°C insodium phosphate buffer (pH 6.5), respectively. i-XAproduced d-ribulose via d-xylulose from d-xyloseat a conversion ratio of d-xylose:d-xylulose:d-ribulose of 72:18:10. Furthermore, d-allulose wasalso produced via d-fructose using d-glucose as thesubstrate, with a d-allulose yield of 11.2%. This isthe first report describing a bacterium expressingd-xylose isomerase and d-allulose 3-epimerase thatconverts readily available sugars such as d-glucoseand d-xylose to rare sugars.

[学科分类] 微生物学和免疫学

[关键词] co-immobilization;d-allulose;d-ketopentoses;enzymatic reaction;one-pot multistep production;Shinella zoogloeoides NN6