| 초록 |
Acetate is a promising carbon source to achieve cost-effective microbial processes because it is abundant and cheap carbon source. In this study, we engineered an Escherichia coli to produce itaconic acid from acetate. Since acetate is known to inhibit cell growth, we screened for a strain with a high tolerance to 10 g/L of acetate in the medium. As a result, the W strain was selected as the host. Subsequently, the WC strain was obtained by overexpression of cad (encoding cis-aconitate decarboxylase) using a synthetic promoter and 5′ UTR. However, the WC strain produced only 0.13 g/L itaconic acid because of low acetate uptake. To improve the production, the acetate assimilating pathway and glyoxylate shunt pathway were amplified by overexpression of pathway genes as well as its deregulation. The resulting strain, WCIAG4 produced 3.57 g/L itaconic acid (16.1% of theoretical maximum yield) after 88 hr of fermentation with rapid acetate assimilation. |
