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Enhanced xylitol production: Expression of xylitol dehydrogenase from Gluconobacter oxydans and mixed culture of resting cell

Paper ID Volume ID Publish Year Pages File Format Full-Text
19952 43150 2016 6 PDF Available
Title
Enhanced xylitol production: Expression of xylitol dehydrogenase from Gluconobacter oxydans and mixed culture of resting cell
Abstract

•The properties and kinetic parameter of xylitol dehydrogenase were determined.•Xylitol dehydrogenase has a NAD(H)-binding motif and a YXXXK active site motif.•Xylitol production was improved by mixed culture with adding exogenous NADH.•The highest yield and volumetric productivity of xylitol were reported.

Xylitol has numerous applications in food and pharmaceutical industry, and it can be biosynthesized by microorganisms. In the present study, xdh gene, encoding xylitol dehydrogenase (XDH), was cloned from the genome of Gluconobacter oxydans CGMCC 1.49 and overexpressed in Escherichia coli BL21. Sequence analysis revealed that XDH has a TGXXGXXG NAD(H)-binding motif and a YXXXK active site motif, and belongs to the short-chain dehydrogenase/reductase family. And then, the enzymatic properties and kinetic parameter of purified recombinant XDH were investigated. Subsequently, transformations of xylitol from d-xylulose and d-arabitol, respectively, were studied through mixed culture of resting cells of G. oxydans wild-type strain and recombinant strain BL21-xdh. We obtained 28.80 g/L xylitol by mixed culture from 30 g/L d-xylulose in 28 h. The production was increased by more than three times as compared with that of wild-type strain. Furthermore, 25.10 g/L xylitol was produced by the mixed culture from 30 g/L d-arabitol in 30 h with a yield of 0.837 g/g, and the max volumetric productivity of 0.990 g/L h was obtained at 22 h. These contrast to the fact that wild-type strain G. oxydans only produced 8.10 g/L xylitol in 30 h with a yield of 0.270 g/g. To our knowledge, these values are the highest among the reported yields and productivity efficiencies of xylitol from d-arabitol with engineering strains.

Keywords
Gluconobacter oxydans; Xylitol dehydrogenase; Mixed culture; Xylitol; Resting cell
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Bioscience and Bioengineering - Volume 122, Issue 3, September 2016, Pages 257–262
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us