Microbial production of multiple short-chain primary amines via retrobiosynthesis.

Bio-based production of many chemicals is not yet possible due to the unknown biosynthetic pathways. Here, we report a strategy combining retrobiosynthesis and precursor selection step to design biosynthetic pathways for multiple short-chain primary amines (SCPAs) that have a wide range of applications in chemical industries. Using direct precursors of 15 target SCPAs determined by the above strategy, Streptomyces viridifaciens vlmD encoding valine decarboxylase is examined as a proof-of-concept promiscuous enzyme both in vitro and in vivo for generating SCPAs from their precursors.

Microbial production of 4-amino-1-butanol, a four-carbon amino alcohol.

4-Amino-1-butanol (4AB) serves as an important intermediate compound for drugs and a precursor of biodegradable polymers used for gene delivery. Here, we report for the first time the fermentative production of 4AB from glucose by metabolically engineered Corynebacterium glutamicum harboring a newly designed pathway comprising a putrescine (PUT) aminotransferase (encoded by ygjG) and an aldehyde dehydrogenase (encoded by yqhD) from Escherichia coli, which convert PUT to 4AB. Application of several metabolic engineering strategies such as fine-tuning the expression levels of ygjG and yqhD, eliminating competing pathways, and optimizing culture condition further improved 4AB production.

Biosynthesis and characterization of poly(d-lactate-co-glycolate-co-4-hydroxybutyrate).

Poly(d-lactate-co-glycolate-co-4-hydroxybutyrate) [poly(d-LA-co-GA-co-4HB)] and poly(d-lactate-co-glycolate-co-4-hydroxybutyrate-co-d-2-hydroxybutyrate) [poly(d-LA-co-GA-co-4HB-co-d-2HB)] are of interest for their potential applications as new biomedical polymers. Here we report their enhanced production by metabolically engineered Escherichia coli. To examine the polymer properties, poly(d-LA-co-GA-co-4HB) polymers having various monomer compositions (3.

A Novel Biosynthetic Pathway for the Production of Acrylic Acid through β-Alanine Route in .

Acrylic acid (AA) is an important industrial chemical used for several applications including superabsorbent polymers and acrylate esters. Here, we report the development of a new biosynthetic pathway for the production of AA from glucose in metabolically engineered through the β-alanine (BA) route. The AA production pathway was partitioned into two modules: an AA forming downstream pathway and a BA forming upstream pathway.

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

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.

Engineering of an oleaginous bacterium for the production of fatty acids and fuels.

Production of free fatty acids (FFAs) and derivatives from renewable non-food biomass by microbial fermentation is of great interest. Here, we report the development of engineered Rhodococcus opacus strains producing FFAs, fatty acid ethyl esters (FAEEs) and long-chain hydrocarbons (LCHCs). Culture conditions were optimized to produce 82.

Metabolic engineering for the production of dicarboxylic acids and diamines.

Microbial production of chemicals and materials from renewable carbon sources is becoming increasingly important to help establish sustainable chemical industry. In this paper, we review current status of metabolic engineering for the bio-based production of linear and saturated dicarboxylic acids and diamines, important platform chemicals used in various industrial applications, especially as monomers for polymer synthesis. Strategies for the bio-based production of various dicarboxylic acids having different carbon numbers including malonic acid (C3), succinic acid (C4), glutaric acid (C5), adipic acid (C6), pimelic acid (C7), suberic acid (C8), azelaic acid (C9), sebacic acid (C10), undecanedioic acid (C11), dodecanedioic acid (C12), brassylic acid (C13), tetradecanedioic acid (C14), and pentadecanedioic acid (C15) are reviewed.

Recent advances in systems metabolic engineering tools and strategies.

Metabolic engineering has been playing increasingly important roles in developing microbial cell factories for the production of various chemicals and materials to achieve sustainable chemical industry. Nowadays, many tools and strategies are available for performing systems metabolic engineering that allows systems-level metabolic engineering in more sophisticated and diverse ways by adopting rapidly advancing methodologies and tools of systems biology, synthetic biology and evolutionary engineering. As an outcome, development of more efficient microbial cell factories has become possible.

Metabolic engineering of Escherichia coli for the production of four-, five- and six-carbon lactams.

Microbial production of chemicals and materials from renewable sources is becoming increasingly important for sustainable chemical industry. Here, we report construction of a new and efficient platform metabolic pathway for the production of four-carbon (butyrolactam), five-carbon (valerolactam) and six-carbon (caprolactam) lactams. This pathway uses ω-amino acids as precursors and comprises two steps.

Bio-based production of monomers and polymers by metabolically engineered microorganisms.

Recent metabolic engineering strategies for bio-based production of monomers and polymers are reviewed. In the case of monomers, we describe strategies for producing polyamide precursors, namely diamines (putrescine, cadaverine, 1,6-diaminohexane), dicarboxylic acids (succinic, glutaric, adipic, and sebacic acids), and ω-amino acids (γ-aminobutyric, 5-aminovaleric, and 6-aminocaproic acids). Also, strategies for producing diols (monoethylene glycol, 1,3-propanediol, and 1,4-butanediol) and hydroxy acids (3-hydroxypropionic and 4-hydroxybutyric acids) used for polyesters are reviewed.

Metabolic engineering of Escherichia coli for the production of 1,3-diaminopropane, a three carbon diamine.

Bio-based production of chemicals from renewable resources is becoming increasingly important for sustainable chemical industry. In this study, Escherichia coli was metabolically engineered to produce 1,3-diaminopropane (1,3-DAP), a monomer for engineering plastics. Comparing heterologous C4 and C5 pathways for 1,3-DAP production by genome-scale in silico flux analysis revealed that the C4 pathway employing Acinetobacter baumannii dat and ddc genes, encoding 2-ketoglutarate 4-aminotransferase and L-2,4-diaminobutanoate decarboxylase, respectively, was the more efficient pathway.

Metabolic engineering of Escherichia coli for enhanced biosynthesis of poly(3-hydroxybutyrate) based on proteome analysis.

We have previously analyzed the proteome of recombinant Escherichia coli producing poly(3-hydroxybutyrate) [P(3HB)] and revealed that the expression level of several enzymes in central metabolism are proportional to the amount of P(3HB) accumulated in the cells. Based on these results, the amplification effects of triosephosphate isomerase (TpiA) and fructose-bisphosphate aldolase (FbaA) on P(3HB) synthesis were examined in recombinant E. coli W3110, XL1-Blue, and W lacI mutant strains using glucose, sucrose and xylose as carbon sources.