Due to the possibility that petroleum supplies will be exhausted in the
next decades to come, more and more attention has been paid to the
production of bacterial pl- tics including polyhydroxyalkanoates (PHA),
polylactic acid (PLA), poly(butylene succinate) (PBS), biopolyethylene
(PE), poly(trimethylene terephthalate) (PTT), and poly(p-phenylene)
(PPP). These are well-studied polymers containing at least one monomer
synthesized via bacterial transformation. Among them, PHA, PLA and PBS
are well known for their biodegradability, whereas PE, PTT and PPP are
probably less biodegradable or are less studied in terms of their
biodegradability. Over the past years, their properties and appli- tions
have been studied in detail and products have been developed. Physical
and chemical modifications to reduce their cost or to improve their
properties have been conducted. PHA is the only biopolyester family
completely synthesized by biological means. They have been investigated
by microbiologists, molecular biologists, b- chemists, chemical
engineers, chemists, polymer experts, and medical researchers for many
years. PHA applications as bioplastics, fine chemicals, implant biomate-
als, medicines, and biofuels have been developed. Companies have been
est- lished for or involved in PHA related R&D as well as large scale
production. It has become clear that PHA and its related technologies
form an industrial value chain in fermentation, materials, feeds, and
energy to medical fields.
