Bioprospects of PHB: A Review

Polyhydroxybutyrates (PHB) are bio-plastics that are produced by many microbial species under carbon rich and nutrient starvation conditions. Poly (ß-hydroxybutyrate) (PHB) belongs to a family of microbial energy/carbon storage compounds collectively known as poly hydroxyalkanoates. The organisms producing PHBs have been isolated, identified and the conditions of maximum production optimized. The cheaper raw material for the mass production of PHB are constantly being studied and suggested to lower the production cost. Most of the commercial productions are at present more expensive than synthetic polymer production. Since biopolymers offer the dual advantage of being formed from renewable resources and in addition to it they are also completely biodegradable, the structure, properties and regulation of synthesis and degradation of PHB should be reviewed and the microbial production of copolymers of 3-hydroxybutyrate and 3-hydroxyvalerate, with properties varying according to copolymer composition, must be considered.