Production of itaconic acid from acetate by engineering acid‐tolerant Escherichia coli W

Abstract

Utilization of abundant and cheap carbon sources can effectively reduce the production cost and enhance the economic feasibility. Acetate is a promising carbon source to achieve cost-effective microbial processes. In this study, we engineered an Escherichia coli strain to produce itaconic acid from acetate. As acetate is known to inhibit cell growth, we initially screened for a strain with a high tolerance to 10 g/L of acetate in the medium, and 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. These efforts support that acetate can be a potential feedstock for biochemical production with engineered E. coli.

Microbial response to acid stress: mechanisms and applications

“…3). Although they share similar (Zhang et al 2008) atpA P. acidipropionici Propionic acid (Guan et al 2014) CgAMD1 C. glabrata Hydrochloric acid (Wu et al 2018) Decarboxylation and deamination cad E. coli Acetic acid (Noh et al 2018) ybaS, gadC E. coli Hydrochloric acid (Lu et al 2013) hdcAPB L. lactis Hydrochloric acid (Trip et al 2012) arcA, arcC, gdh, gadB, ybaS P. acidipropionici Propionic acid (Guan et al 2016) Cell resistance mechanisms, different species utilize a variety of specific elements as a response to acid stress. Therefore, customized strategies must be proposed for different strains.…”

Enhancing rhamnolipids production and exploring the mechanism of low-foaming fermentation under weakly acidic conditions

“…These results suggested that enhancing rhamnolipids production by mutagenesis was a promising strategy to realize low-foaming rhamnolipids fermentation under weakly acid conditions. In addition, other methods for strain improvement like metabolic engineering and synthetic biology techniques [37,38] should be included in future studies for improving rhamnolipids productivity under weakly acid conditions.…”

Auxotrophic Selection Strategy for Improved Production of Coenzyme B12 in Escherichia coli

“…Therefore, we tried to deregulate the expression of metH using synthetic constitutive promoters (http:// parts.igem.org/Promoters/Catalog/Anderson) Noh et al, 2018Noh et al, , 2017. To restore the cell biomass, the metH expression needed to be increased than before as its insufficient expression produced less cell biomass.…”