Polyhydroxyalkanoates as a source of chemicals, polymers, and biofuels.

Microbial polyhydroxyalkanoates (PHA) are a family of structurally diverse polyesters produced by many bacteria. Deleting key steps from the beta-oxidation cycle in Pseudomonas putida makes it possible to achieve precise substrate based design of PHA homopolymers, copolymers, and block polymers, allowing the study of structure-property relationship in a clear way. The PHA homopolymer synthesis also allows the microbial or chemical production of pure monomers of PHA in a convenient way without separating the mixed monomers. After used as bioplastics, PHA can be methyl esterified to become biofuels, which further extends the PHA application value. The microbial production of PHA with diverse structures is entering a new developing phase.