Petroleum-based plastics constitute a major environmental problem due to their low biodegradability
and accumulation in various environments. Therefore, searching for novel biodegradable plastics is
of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable
plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this
report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of
PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms
during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy
reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two
main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium
for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic
analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA
synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining
with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs
produced were characterized by GC–MS. Diverse substrates for the production of PHAs in strain LB400
were analyzed.