Modern biopolyamide-based materials: synthesis and modification

Radzik, Paulina; Leszczyńska, Agnieszka; Pielichowski, Krzysztof

doi:10.1007/s00289-019-02718-x

Cited by 54 publications

(28 citation statements)

References 94 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As for the other polymer types discussed in this review, commercial PA production is currently based on non-renewable raw materials, and efforts are ongoing towards the identification of renewable monomers, especially focusing on novel diamine and diacid reagents. 27,162,169 The use of terpene-based monomers in PA polymer formation, however, remains underexplored.…”

Section: Polyamidesmentioning

confidence: 99%

From terpenes to sustainable and functional polymers

2020

View full text Add to dashboard Cite

show abstract

Section: Polyamidesmentioning

confidence: 99%

From terpenes to sustainable and functional polymers

2020

View full text Add to dashboard Cite

show abstract

“…Biopolyamides are gaining more interest for use in the textile and construction industries. Polyamides can be obtained either by condensation of dicarboxylic acids with diamines or by anionic ring-opening polymerization of lactams, the cyclization products of ω-amino acids [ 2 ]. Bio-based production of monomeric building blocks for polyamides has been established in metabolically engineered C. glutamicum and E. coli [ 3 , 4 ].…”

Section: Introductionmentioning

confidence: 99%

Adaptive laboratory evolution accelerated glutarate production by Corynebacterium glutamicum

et al. 2021

View full text Add to dashboard Cite

Background The demand for biobased polymers is increasing steadily worldwide. Microbial hosts for production of their monomeric precursors such as glutarate are developed. To meet the market demand, production hosts have to be improved constantly with respect to product titers and yields, but also shortening bioprocess duration is important. Results In this study, adaptive laboratory evolution was used to improve a C. glutamicum strain engineered for production of the C5-dicarboxylic acid glutarate by flux enforcement. Deletion of the l-glutamic acid dehydrogenase gene gdh coupled growth to glutarate production since two transaminases in the glutarate pathway are crucial for nitrogen assimilation. The hypothesis that strains selected for faster glutarate-coupled growth by adaptive laboratory evolution show improved glutarate production was tested. A serial dilution growth experiment allowed isolating faster growing mutants with growth rates increasing from 0.10 h−1 by the parental strain to 0.17 h−1 by the fastest mutant. Indeed, the fastest growing mutant produced glutarate with a twofold higher volumetric productivity of 0.18 g L−1 h−1 than the parental strain. Genome sequencing of the evolved strain revealed candidate mutations for improved production. Reverse genetic engineering revealed that an amino acid exchange in the large subunit of l-glutamic acid-2-oxoglutarate aminotransferase was causal for accelerated glutarate production and its beneficial effect was dependent on flux enforcement due to deletion of gdh. Performance of the evolved mutant was stable at the 2 L bioreactor-scale operated in batch and fed-batch mode in a mineral salts medium and reached a titer of 22.7 g L−1, a yield of 0.23 g g−1 and a volumetric productivity of 0.35 g L−1 h−1. Reactive extraction of glutarate directly from the fermentation broth was optimized leading to yields of 58% and 99% in the reactive extraction and reactive re-extraction step, respectively. The fermentation medium was adapted according to the downstream processing results. Conclusion Flux enforcement to couple growth to operation of a product biosynthesis pathway provides a basis to select strains growing and producing faster by adaptive laboratory evolution. After identifying candidate mutations by genome sequencing causal mutations can be identified by reverse genetics. As exemplified here for glutarate production by C. glutamicum, this approach allowed deducing rational metabolic engineering strategies.

show abstract

“…Among bioplastics, the biopolyamides find many applications ranging from the production of parachutes during World War II to filaments for 3D-printing at present [2,3]. Polyamides can be produced via two routes: either by the condensation of dicarboxylic acids with diamines or by the anionic ring-opening polymerization of lactams, which can be formed from ω-amino acids via cyclization [4]. Examples of these main building blocks range from succinate to sebacate for 2 of 15 dicarboxylic acids, from putrescine to hexamethylenediamine for diamines, and from γ-aminobutyrate (GABA) to ε-aminocaproate (6ACA) for ω-amino acids.…”

Section: Introductionmentioning

confidence: 99%

Flux Enforcement for Fermentative Production of 5-Aminovalerate and Glutarate by Corynebacterium glutamicum

et al. 2020

View full text Add to dashboard Cite

Bio-based plastics represent an increasing percentage of the plastics economy. The fermentative production of bioplastic monomer 5-aminovalerate (5AVA), which can be converted to polyamide 5 (PA 5), has been established in Corynebacterium glutamicum via two metabolic pathways. l-lysine can be converted to 5AVA by either oxidative decarboxylation and subsequent oxidative deamination or by decarboxylation to cadaverine followed by transamination and oxidation. Here, a new three-step pathway was established by using the monooxygenase putrescine oxidase (Puo), which catalyzes the oxidative deamination of cadaverine, instead of cadaverine transaminase. When the conversion of 5AVA to glutarate was eliminated and oxygen supply improved, a 5AVA titer of 3.7 ± 0.4 g/L was reached in microcultivation that was lower than when cadaverine transaminase was used. The elongation of the new pathway by 5AVA transamination by GABA/5AVA aminotransferase (GabT) and oxidation by succinate/glutarate semialdehyde dehydrogenase (GabD) allowed for glutarate production. Flux enforcement by the disruption of the l-glutamic acid dehydrogenase-encoding gene gdh rendered a single transaminase (GabT) in glutarate production via the new pathway responsible for nitrogen assimilation, which increased the glutarate titer to 7.7 ± 0.7 g/L, i.e., 40% higher than with two transaminases operating in glutarate biosynthesis. Flux enforcement was more effective with one coupling site, thus highlighting requirements regarding the modularity and stoichiometry of pathway-specific flux enforcement for microbial production.

show abstract

Modern biopolyamide-based materials: synthesis and modification

Cited by 54 publications

References 94 publications

From terpenes to sustainable and functional polymers

From terpenes to sustainable and functional polymers

Adaptive laboratory evolution accelerated glutarate production by Corynebacterium glutamicum

Flux Enforcement for Fermentative Production of 5-Aminovalerate and Glutarate by Corynebacterium glutamicum

Contact Info

Product

Resources

About