Biosynthesis of glycolate-based polyesters containing medium-chain-length 3-hydroxyalkanoates in recombinant Escherichia coli expressing engineered polyhydroxyalkanoate synthase

Abstract

Glycolate(GL)-based polyesters were for the first time produced in the recombinant Escherichia coli fatty acid -oxidation pathway reinforcing mutant LS5218, using extracellularly added GL as a monomer precursor. Cells expressing a Ser325Thr/Gln481Lys mutant of polyhydroxyalkanoate synthase (PhaC1STQK) from Pseudomonas sp. 61-3, propionyl-CoA transferase from Megasphaera elsdenii and enoyl-CoA hydratase from Pseudomonas aeruginosa grown on GL and dodecanoate were found to produce novel copolymers of GL with 3-hydroxyalkanoates (3HAs) (C 4 -C 12 ), P(GL-co-3HA), with a weight-average molecular weight of 34 000. The 1 H NMR analysis of the copolymer revealed the incorporation of GL units into the polymer chain. This result demonstrates that PhaC1STQK polymerized glycolyl-CoA as a monomer substrate. Additionally, the novel lactate(LA)-based polyester P(LA-co-3HA) was produced by substituting GL with LA, indicating that the method is versatile and allows the production of a variety of biopolymers. Keywords:poly (glycolide) poly (lactide) lactate-polymerizing enzyme biobased plastic polyhydroxyalkanoate

Enzymes catalysing the synthesis and degradation of beta-linked biopolymers and their applications

“…This study demonstrated the effectiveness of the enzyme engineering of LPE in two directions: improved LA incorporation and polymer yield for both aerobic and anaerobic culture conditions [76]. Furthermore, copolymers incorporating 2-hydroxy acids (2HAs), such as 2-hydroxybutyrate [77,78] and glycolate [79,80], may lead to copolymers with novel properties, including biodegradability ( Figure 3). This expansion of PHA synthase to 2HA--polymerizing enzymes has prompted us to create additional enzymes with acquired activity towards new and unusual monomer substrates, resulting in new polymers.…”

Biodegradable Polymers: Recent Developments and New Perspectives

“…This study demonstrated the effectiveness of the enzyme engineering of LPE in two directions: improved LA incorporation and polymer yield for both aerobic and anaerobic culture conditions [76]. Furthermore, copolymers incorporating 2-hydroxy acids (2HAs), such as 2-hydroxybutyrate [77,78] and glycolate [79,80], may lead to copolymers with novel properties, including biodegradability ( Figure 3). This expansion of PHA synthase to 2HA--polymerizing enzymes has prompted us to create additional enzymes with acquired activity towards new and unusual monomer substrates, resulting in new polymers.…”

Revelation of the ability of Burkholderia sp. USM (JCM 15050) PHA synthase to polymerize 4-hydroxybutyrate monomer

“…PHA synthase was expressed in E . coli for the synthesis of glycolate-based polyesters containing medium-chain-length 3-hydroxyalkanoates (Matsumoto et al, [2011]).…”