Biodegradable plastics. (Bioplastic) is a compound produced by the organism. Bioplastics can be decomposed by microorganisms in the environment. Polyhydroxybutyrate (PHB) is bioplastic, the most common representative of polyhydroxyalkanoates (PHAs). PHB produced by various microorganisms because of their minimal nutrient requirement for growth including cyanobacteria. PHB also has physical and chemical properties that similar to synthetic plastics from petrochemicals.