Bioplastics production from microalgae
Friday October 21 2011
Poly-3-hydroxybutyrate (PHB) is a thermoplastic polyester which occurs naturally in bacteria as Ralstonia eutropha and Bacillus megaterium. Even though PHB is biodegradable and is not dependent on fossil resources, this bioplastic has been traditionally too expensive to produce to replace petroleum-based plastics. Research led by Franziska Hempel from the LOEWE-Centre Synmikro in Germany describes an alternative method of producing PHB in microalgae. Findings are reported in the open access journal Microbial Cell Factories (2011, 10:81).
PHB is synthesised in bacteria from acetyl-CoA using the enzymes ß-ketothiolase, acetoacetyl-CoA reductase and PHB synthase. The genes coding for these proteins were inserted into a diatom (Phaeodactylum tricornutum) resulting in expression of the enzymes and synthesis of PHB in cytosolic granules. After only seven days, about 10% of the dried weight of the diatoms was PHB.