The ‘PHAome’

Polyhydroxyalkanoates (PHAs) are a family of polyesters synthesized by bacteria. Similarly to the genome, transcriptome, and proteome (the entire array of nucleic acids and proteins present in a cell or population of cells at a given time), the PHA spectrum exhibits diverse and dynamic modifications – the ‘PHAome’ – reflecting not only by the diversity of monomers, homopolymers, random and block copolymers, functional and graft polymers, molecular weights, and combinations of the above, but also the ranges of PHAs with various molecular weights and monomer ratios that are present at a particular timepoint in a bacterial cell. Echoing the Materials Genome Initiative (MGI) launched in 2011 to develop an infrastructure to accelerate advanced materials discovery and deployment, understanding the PHAome and ensuring an ample supply of PHAs based on it will promote the discovery of new properties and applications of this family of advanced materials.

TrendsPHA diversity (PHAome) has been rapidly increased due to the increasing diversities of monomers, homopolymers, random and block copolymers, functional and graft polymers, molecular weights, and combinations of the above. The successful manipulation of β-oxidation in Pseudomonas spp. allows all the above diversity be well controlled.New PHAs are continuously produced by the biological communities. A MGI similar infrastructure created by PHA research communities should enable scientists and engineers to design new materials, and also help move the PHAome faster to the market place.It has become increasing possible to obtain PHA diversity in a single bacterial species, the ‘platform bacterium’, under various growth conditions. A Halomonas sp. able to grow under open and continuous culture to a high cell density containing high PHA content is an ideal platform bacterium.