Pathway Construction in Corynebacterium glutamicum and Strain Engineering To Produce Rare Sugars from Glycerol
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- 作者：Jiangang YangYueming Zhu ; Yan Men ; Shangshang Sun ; Yan Zeng ; Ying Zhang ; Yuanxia Sun ; Yanhe Ma
- 刊名：Journal of Agricultural and Food Chemistry
- 出版年：2016
- 出版时间：December 21, 2016
- 年：2016
- 卷：64
- 期：50
- 页码：9497-9505
- 全文大小：518K
- ISSN：1520-5118
文摘
Rare sugars are valuable natural products widely used in pharmaceutical and food industries. In this study, we expected to synthesize rare ketoses from abundant glycerol using dihydroxyacetone phosphate (DHAP)-dependent aldolases. First, a new glycerol assimilation pathway was constructed to synthesize DHAP. The enzymes which convert glycerol to 3-hydroxypropionaldehyde and mallcaps">l-glyceraldehyde were selected, and their corresponding aldehyde synthesis pathways were constructed in vivo. Four aldol pathways based on different aldolases and phosphorylase were gathered. Next, three pathways were assembled and the resulting strains synthesized 5-deoxypsicose, 5-deoxysorbose, and 5-deoxyfructose from glucose and glycerol and produce mallcaps">l-fructose, mallcaps">l-tagatose, mallcaps">l-sorbose, and mallcaps">l-psicose with glycerol as the only carbon source. To achieve higher product titer and yield, the recombinant strains were further engineered and fermentation conditions were optimized. Fed-batch culture of engineered strains obtained 38.1 g/L 5-deoxypsicose with a yield of 0.91 ± 0.04 mol product per mol of glycerol and synthesized 20.8 g/L mallcaps">l-fructose, 10.3 g/L mallcaps">l-tagatose, 1.2 g/L mallcaps">l-sorbose, and 0.95 g/L mallcaps">l-psicose.