Medium-chain-length poly-3-hydroxyalkanoates (mcl-PHAs) were
discovered in the 1980s, 60 years after their more famous biopolyester ancestor poly--
-hydroxybutyrate. Accumulated only by a group of related Pseudomonas species, these
polyesters are remarkable in their structural diversity and applications. mcl-PHAs are
highly water resistant, yet readily susceptible to enzymatic degradation. They can be
used in packaging, paints, toners, adhesives and in many biomedical applications but
have yet to be produced commercially. mcl-PHAs are most efficiently produced from
carboxylic (fatty) acids such as octanoic acid but can also be produced from many nonrelated
substrates such as glucose. Recent advances in fermentation and separation
processes, as well as strain development are improving polymer quality and reducing
production cost, which should soon lead to the adoption of mcl-PHAs by industry.
Keywords: Applications, Biosynthesis, mcl-PHA, Medium-chain-length PHA
(mcl-PHA), Poly-3-hydroxyalkanoate, Production, Recovery, Thermoelastomer.
