Tacticity Characterization of Biosynthesized Polyhydroxyalkanoates Containing ()- and ()-3-Hydroxy-2-Methylpropionate Units.

Polyhydroxyalkanoates (PHAs), aliphatic polyesters synthesized by microorganisms, have gained considerable attention as biodegradable plastics. Recently, α-carbon-methylated PHAs have been shown to exhibit several interesting properties that differ from those of conventional PHAs, such as their crystallization behavior and material properties. This study investigated α-carbon methylated ()- and ()-3-hydroxy-2-methylpropionate (3H2MP) as new repeating units.

Exploring Class I polyhydroxyalkanoate synthases with broad substrate specificity for polymerization of structurally diverse monomer units.

Polyhydroxyalkanoate (PHA) synthases (PhaCs) are key enzymes in PHA polymerization. PhaCs with broad substrate specificity are attractive for synthesizing structurally diverse PHAs. In the PHA family, 3-hydroxybutyrate (3HB)-based copolymers are industrially produced using Class I PhaCs and can be used as practical biodegradable thermoplastics.

Poly(3-mercapto-2-methylpropionate), a Novel α-Methylated Bio-Polythioester with Rubber-like Elasticity, and Its Copolymer with 3-hydroxybutyrate: Biosynthesis and Characterization.

A new polythioester (PTE), poly(3-mercapto-2-methylpropionate) [P(3M2MP)], and its copolymer with 3-hydroxybutyrate (3HB) were successfully biosynthesized from 3-mercapto-2-methylpropionic acid as a structurally-related precursor. This is the fourth PTE of biological origin and the first to be α-methylated. P(3M2MP) was biosynthesized using an engineered LSBJ, which has a high molecular weight, amorphous structure, and elastomeric properties, reaching 2600% elongation at break.