Polyhydroxyalkanoates (PHA

In recent years polyhydroxyalkanoates (PHAs) have received considerable attention due to their diverse properties regarding thermoplastic and elastomeric nature as well as biocompatibility and biodegradability. PHAs produce by bacteria in the form of storage compound as carbon and energy source under the stress of nutrient(s) in the availability of abundant carbon source. While bacteria come under the stress of nutrient these energy storage compounds are break down in smaller fragments that degraded and consumed by bacterial cells. Polyhydroxyalkanoates (PHAs) create an ultimate carbon and energy storage material because of their lower solubility and high molecular weight, which apply slight osmotic pressure on the cell of bacterial species (Sudesh et al., 2000; Peters and Rehm, 2005; Keshavarz and Roy, 2010). …show more content…
Additionally, on the basis of types of monomer present in the polymeric chain, PHAs can be a homopolymer containing only one type of hydroxyalkanoate as the monomer unit like P(3HB), and P(3HHx). When more than one types of hydroxyalkanoate as monomer units are exist, they are often called heteropolymer such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate), P(3HB-co-3HV), poly(3-hydroxyhexanoate-co-3-hydroxyoctanoate), P(3HHx-co-3HO) and poly-(3-hydroxybutyrate-co-3- hydroxyhexanoate), P(3HB-co-3HHx).The microorganism used in production process and the growth conditions conclude the molecular weight of these polymers that ranged between 2×105 and