Metabolic Engineering of Recombinant E. coli for the Production of 3‐Hydroxypropionate

Microbial response to acid stress: mechanisms and applications

“…As an environmentally friendly and renewable process, microbial synthesis of many valuable products through fermentation has become an ideal substitution for traditional synthetic methods such as chemical and enzymatic synthesis. Higher acid tolerance adopted by microbial producers enhances their stability during the synthetic process in which acids accumulate (Hasunuma et al 2011;Lipscomb et al 2012). In both cases, namely, undesired pathogenic organisms and desired microbial producers, understanding of the underlying mechanisms of acid tolerance is vital for further applications of these microorganisms.…”

Introduction of a Synthetic CO2-fixing Photorespiratory Bypass into a Cyanobacterium

“…Accumulation of 3OHP, the product of MCR, can lead to organic acid toxicity (19); propionyl-CoA, the product of PCS, inhibits both pyruvate dehydrogenase and citrate synthase (20). The potential toxicity in conjunction with the difficulty of successfully reconstituting multistep metabolic pathways (21) presented major challenges.…”

“…On the other hand, pyruvate or intermediates in the synthetic bypass could be redirected for biotechnological applications, such as biofuels or replacements for chemical feedstocks that are currently petroleum-derived (19). For example, we have shown that 3OHP, a precursor for bioplastics, can be derived from malonylCoA by the heterologous expression of MCR in cyanobacteria.…”

“…For example, we have shown that 3OHP, a precursor for bioplastics, can be derived from malonylCoA by the heterologous expression of MCR in cyanobacteria. Developing cyanobacteria as production strains requires increasing their tolerance to higher concentrations of 3OHP; this has been accomplished in E. coli (19). Likewise, the production of propionyl-CoA by the combined function of MCR and PCS in the synthetic bypass could be useful for the production of diverse polyhydroxyalkanoates such as polyhydroxyvalerate, polyhydroxymethylvalerate, or co-polymers.…”

Recent advances, challenges and metabolic engineering strategies in the biosynthesis of 3‐hydroxypropionic acid

“…Recently, different studies have been performed to reduce the toxic effect of 3‐HP (Figure 6). One way is to overexpress several metabolic pathways for the production of chorismate, nucleotides, polyamines, and threonine/homocysteine or to supplement these metabolites in the medium (Lipscomb et al, 2012). In another study, a novel small open reading frame (sORF) named iroK, encoding a 21 amino acid peptide, was identified, and it conferred a 133% increase in resistance to 3‐HP when it was translated (TE Warnecke et al, 2012).…”