Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4753208 | Journal of Bioscience and Bioengineering | 2017 | 5 Pages |
Abstract
Due to the decrease of intracellular NADH availability, gluconate metabolism is more conducive to pyruvate production than glucose. Transcriptome analysis revealed that the Entner-Doudoroff (ED) pathway was activated by gluconate in Escherichia coli YP211 (MG1655 ÎldhA ÎpflB Îpta-ackA ÎpoxB Îppc ÎfrdBC). To construct a new pyruvate producing strain with glucose metabolism via ED pathway, the genes ppsA, ptsG, pgi and gnd were deleted sequentially to reduce the demand for PEP and block the Embden-Meyerhor-Parnas pathway and Pentose-Phosphate pathway. After nearly 1000 generations of growth-based selection, the evolved strain YP404 was isolated and the ED pathway was proved to be activated as the primary glycolytic pathway. Comparing with YP211, the pyruvate concentration and yield increased by 59% and 10.1%, respectively. In fed-batch fermentation, the pyruvate concentration reached 83.5 g lâ1 with a volumetric productivity of 2.3 g lâ1 hâ1. This was the first time to produce pyruvate via ED pathway, and prove that this was a more effective way.
Related Topics
Physical Sciences and Engineering
Chemical Engineering
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Authors
Maohua Yang, Ruonan Chen, Tingzhen Mu, Xiang Zhang, Jianmin Xing,