Improved Xylitol Production from d-Arabitol by Enhancing the Coenzyme Regeneration Efficiency of the Pentose Phosphate Pathway in Gluconobacter oxydans

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• 作者：Sha Li ; Jinliang Zhang ; Hong Xu ; Xiaohai Feng
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2016
• 出版时间：February 10, 2016
• 年：2016
• 卷：64
• 期：5
• 页码：1144-1150
• 全文大小：329K
• ISSN：1520-5118

文摘

Gluconobacter oxydans is used to produce xylitol from d-arabitol. This study aims to improve xylitol production by increasing the coenzyme regeneration efficiency of the pentose phosphate pathway in G. oxydans. Glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) were overexpressed in G. oxydans. Real-time PCR and enzyme activity assays revealed that G6PDH/6PGDH activity and coenzyme regeneration efficiency increased in the recombinant G. oxydans strains. Approximately 29.3 g/L xylitol was obtained, with a yield of 73.2%, from 40 g/L d-arabitol in the batch biotransformation with the G. oxydans PZ strain. Moreover, the xylitol productivity (0.62 g/L/h) was 3.26-fold of the wild type strain (0.19 g/L/h). In repetitive batch biotransformation, the G. oxydans PZ cells were used for five cycles without incurring a significant loss in productivity. These results indicate that the recombinant G. oxydans PZ strain is economically feasible for xylitol production in industrial bioconversion.