High‐level production of 3‐hydroxypropionic acid from glycerol as a sole carbon source using metabolically engineered Escherichia coli

Abstract

As climate change is an important environmental issue, the conventional petrochemical‐based processes to produce valuable chemicals are being shifted toward eco‐friendly biological‐based processes. In this study, 3‐hydroxypropionic acid (3‐HP), an industrially important three carbon (C3) chemical, was overproduced by metabolically engineered Escherichia coli using glycerol as a sole carbon source. As the first step to construct a glycerol‐dependent 3‐HP biosynthetic pathway, the dhaB1234 and gdrAB genes from Klebsiella pneumoniae encoding glycerol dehydratase and glycerol reactivase, respectively, were introduced into E. coli to convert glycerol into 3‐hydroxypropionaldehyde (3‐HPA). In addition, the ydcW gene from K. pneumoniae encoding γ‐aminobutyraldehyde dehydrogenase, among five aldehyde dehydrogenases examined, was selected to further convert 3‐HPA to 3‐HP. Increasing the expression level of the ydcW gene enhanced 3‐HP production titer and reduced 1,3‐propanediol production. To enhance 3‐HP production, fed‐batch fermentation conditions were optimized by controlling dissolved oxygen (DO) level and employing different feeding strategies including intermittent feeding, pH‐stat feeding, and continuous feeding strategies. Fed‐batch culture of the final engineered E. coli strain with DO control and continuous feeding strategy produced 76.2 g/L of 3‐HP with the yield and productivity of 0.457 g/g glycerol and 1.89 g·L−1·h−1, respectively. To the best of our knowledge, this is the highest 3‐HP productivity achieved by any microorganism reported to date.

Fermentative High-Level Production of 5-Hydroxyvaleric Acid by Metabolically Engineered Corynebacterium glutamicum

“…Since 5-HV is a highly reduced chemical, it was reasoned that metabolic flux was not sufficiently directed to yield 5-HV compared to that toward glutaric acid production during cultivation. Some reports have indicated that optimization of cultivation conditions such as aeration rates and/or dissolved oxygen levels needs to be studied for supporting enhanced production of target chemicals with a reduced form such as 4-hydroxybutyrate and 3-hydroxypropionate without by-product formation. , Process engineering used for the enhanced production of such chemicals provides a good reference for producing 5-HV as well as reducing by-product accumulation. Furthermore, because a high amount of cofactors such as NADPH and/or NADH is required to synthesize not only 5-HV but also l -lysine, the formation of glutaric acid by dehydrogenation of glutarate semialdehyde coupled with reduction of NAD­(P) + to NAD­(P)H is inevitable in the l -lysine-overproducing strain.…”

Notable Improvement of 3-Hydroxypropionic Acid and 1,3-Propanediol Coproduction Using Modular Coculture Engineering and Pathway Rebalancing

“…Second, development and optimization of cheap media − for growing the bacterial biomass would significantly decrease the biomass production costs. Third, biomass production of both L. reuteri and E. coli strains can be done together as reported earlier, by redesigning the gene with noninducible promoters , and an antibiotic selection marker in the plasmid that would not affect the growth of L. reuteri during cocultured growth with the recombinant E. coli strain. Regarding the technological configurations, sequential feeding of glycerol and cells would be the best option for 3-HP and 1,3-PDO production as it provided the highest titer of both metabolites.…”

“…In recent years, there has been a growing popularity of producing high-value platform chemicals from wastes. , 3-Hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3-PDO) are two important building-block materials that have multiple applications in the food, cosmetics, polymer, and chemical industries. − Biomanufacturing of 3-HP and 1,3-PDO from glycerol is becoming increasingly important for its simultaneous management and valorization, since glycerol is a byproduct of biodiesel industries. − The commercial potentials of 3-HP and 1,3-PDO have been estimated as over $10 billion and $600 million, respectively. , Bioproduction of 3-HP and 1,3-PDO generally starts with glycerol conversion into a metabolic intermediate, 3-hydroxypropionaldehyde (3-HPA), by a coenzyme-B 12 -dependent glycerol dehydratase (GDHt, encoded by dhaB ). 3-HPA is then converted to 3-HP by an NAD + -dependent aldehyde dehydrogenase (AldH, e.g., GabD4 of Cupriavidus necator ) and 1,3-PDO by an NADH-dependent 1,3-PDO oxidoreductase (PDOR, encoded by dhaT ; Figure a).…”

Heterologous Production of Acrylic Acid: Current Challenges and Perspectives

“…The glycerol route (CoA-independent) is probably the route most studied as 3-HP can be produced directly from glycerol in two steps (Figure 3) [36,52,[67][68][69][70]. Additionally, 3-HP can also be produced from glucose using glycerol as an intermediary [32,34,35,38,39,44,45,47,51,[71][72][73][74].…”

“…In the past years, AA heterologous production has significantly evolved due to all the efforts made in the past focussing on the biosynthesis of 3-hydroxypropionic acid (3-HP), a possible intermediary compound in AA biosynthesis. 3-HP bio-based production has been intensively studied, and up to 125.93 g/L concentrations have already been obtained using different pathways and hosts [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50][51][52][53]. This acid can be converted to AA by catalysis (dehydrogenation) or, more recently, by fermentation.…”