Polyhydroxyalkanoates

Polyhydroxyalkanoates (PHA) are polyesters produced in nature by numerous microorganisms, including through bacterial fermentation of sugar or lipids. When produced by bacteria they serve as both a source of energy and as a carbon sink.

Production

PHA is produced by microorganisms (like Alcaligenes eutrophus or Ralstonia eutropha and Bacillus megaterium) under nutrient-limiting conditions with excess carbon. This process involves the conversion of carbon sources, like glucose, to PHA by the action of certain enzymes.

Structure

Polyhydroxyalkanoates are linear polyesters produced in nature by bacterial fermentation of sugar or lipids. They are produced by the bacteria to store carbon and energy. More than 150 different monomers can be combined within this family to give materials with extremely different properties. These plastics are biodegradeable and are used in the production of bioplastics.

Uses

PHA is used in the production of bioplastics. They are also used in the medical field for the production of sutures, slings, bone plates, and skin substitutes.

Environmental Impact

PHA is a biodegradable plastic that can be composted and digested. It does not produce toxic byproducts when degraded, unlike many other plastics.

See Also

• Bioplastics
• Bacterial fermentation
• Polyester