Microbial Biosynthesis of ε-Poly-L-Lysine

ε-Poly-L-lysine is a naturally occurring homopolyamide comprising repeated L-lysine residues linked via ε-amine to α-carboxyl isopeptide bonds. It is chiefly synthesised by filamentous actinomycetes, notably Streptomyces albulus, through a dedicated nonribosomal peptide synthetase that activates and polymerises lysine in an ATP-dependent manner. Biosynthesis commences with the uptake or intracellular synthesis of L-lysine via the diaminopimelate pathway, followed by adenylation of the ε-amine group, thioester formation on a peptidyl carrier protein and iterative condensation to give polymers of 25–40 monomer units. Intracellular ATP supply, regulation of key metabolic nodes and expression of the ε-PL synthetase gene are all critical determinants of yield. Downstream, the polymer is secreted into the culture medium and recovered by ion-exchange and precipitation processes. Owing to its broad-spectrum antimicrobial properties, biodegradability and lack of toxicity, ε-poly-L-lysine finds widespread use as a food preservative, in pharmaceuticals and in advanced material applications. Advances in strain engineering, process control and systems biology continue to enhance productivity and cost-effectiveness, widening its commercial and environmental impact.

Research from Nature Portfolio

No recent Nature Portfolio content available.

Microbial Biosynthesis of ε-Poly-L-Lysine publication trend

The graph below shows the total number of articles in microbial biosynthesis of ε-poly-l-lysine across all publications each year (not limited to Nature Index journals).

Technical terms

Nonribosomal peptide synthetase (NRPS): A multi-domain enzyme that assembles peptides independently of the ribosome by activating amino acids and catalysing peptide bond formation.

Isopeptide bond: A peptide linkage formed between the ε-amino group of one amino acid and the α-carboxyl group of another, distinct from the standard α-amide bond.

Adenylation domain: The NRPS subunit responsible for ATP-driven activation of an amino acid to form an aminoacyl-adenylate intermediate.

Polyphosphate kinase (PPK): An enzyme that transfers phosphate from inorganic polyphosphate to ADP or AMP, thereby regenerating ATP inside cells.

Multi-omics: An integrative analytical approach combining genomics, transcriptomics and metabolomics to elucidate cellular pathways and regulatory networks.

References

1. Engineering Streptomyces albulus to enhance ε-poly-L-lysine production by introducing a polyphosphate kinase-mediated ATP regeneration system. Microbial Cell Factories (2023).
2. Enhanced ε-Poly-L-Lysine Production in Streptomyces albulus through Multi-Omics-Guided Metabolic Engineering. Biomolecules (2024).
3. Recent advances in microbial ε-poly-L-lysine fermentation and its diverse applications. Biotechnology for Biofuels and Bioproducts (2022).