Glossary term


Polyhydroxyalkanoates (PHA) or the polyhydroxy fatty acids, are a family of biodegradable polyesters. As in many mammals, including humans, that hold energy reserves in the form of body fat there are also bacteria that hold intracellular reserves in for of polyhydroxy alkenoates. Here the microorganisms store a particularly high level of energy reserves (up to 80% of their own body weight) for when their sources of nutrition become scarce. By farming this type of bacteria, and feeding them on sugar or starch (mostly from maize), or at times on plant oils or other nutrients rich in carbonates, it is possible to obtain PHA‘s on an industrial scale. [11] The most common types of PHA are PHB (Polyhydroxy butyrate, PHBV and PHBH. Depending on the bacteria and their food, PHAs with different mechanical properties, from rubbery soft trough stiff and hard as ABS, can be produced. Some PHSs are even biodegradable in soil or in a marine environment.