Production of Polyhydroxyalkanoates by Paraburkholderia and Burkholderia Species

Species of the genera Paraburkholderia and Burkholderia are versatile bacteria that live in a wide range of ecological niches. Paraburkholderia and Burkholderia strains have been used in various biotechnological applications, including bioremediation of pollutants, plant-growth promotion, and synthesis of polyhydroxyalkanoates (PHA). The aims of this study are to analyze the genes and metabolic pathways for the synthesis of PHA from diverse substrates by Paraburkholderia and Burkholderia species and to discuss biomedical and biotechnological applications of these biopolymers. The genes encoding enzymes and proteins involved in PHA metabolism of diverse Paraburkholderia and Burkholderia species were identified and characterized by genomic analyses. The metabolic routes of PHA synthesis and the metabolism of substrates that are channeled into the biosynthesis of PHA by Paraburkholderia and Burkholderia are described. Most species of Paraburkholderia and Burkholderia genera have class I PHA synthases. In general, strains belonging to these genera synthesize short-chain-length PHA (scl-PHA), including homopolymers and copolymers. Specifically, P. sacchari strain LMG 19450, P. xenovorans LB400, B. cepacia ATCC 17759, and B. thailandensis E264 are relevant strains for PHA production. Biomedical applications of bacterial PHA include their use in scaffold design for tissue engineering; moreover, PHA have also been extensively applied in packaging materials.