Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6494721 | Metabolic Engineering | 2013 | 7 Pages |
Abstract
The expression levels of sorbose/sorbosone dehydrogenase genes (sdh and sndh) and the synthesis genes (pqqABCDEN) of the adjoint cofactor pyrroloquinoline quinone (PQQ) were genetically manipulated in Ketogulonigenium vulgare to increase the production of 2-keto-l-gulonic acid (2-KLG), the precursor of vitamin C, in the consortium of K. vulgare and Bacillus cereus. We found that overexpression of sdh-sndh alone in K. vulgare could not significantly enhance the production of 2-KLG, revealing the cofactor PQQ was required for the biosynthesis of 2-KLG. Various expression levels of PQQ were achieved by differential expression of pqqA, pqqABCDE and pqqABCDEN, respectively. The combinatorial expression of sdh/sndh and pqqABCDEN in K. vulgare enabled a 20% increase in the production of 2-KLG (79.1±0.6 g lâ1) than that of the parental K. vulgare (65.9±0.4 g lâ1) in shaking flasks. Our results demonstrated the balanced co-expression of both the key enzymes and the related cofactors was an efficient strategy to increase chemicals' biosynthesis.
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Authors
Jin Du, Wei Bai, Hao Song, Ying-Jin Yuan,