A review on production of poly β hydroxybutyrates from cyanobacteria for the production of bio plastics

• The importance and awareness of using cyanobacteria as PHB resource are reported.
• Genetic engineering of microorganisms to introduce pathways in PHB discussed.
• Alternative substrates and novel extraction methods of PHB are discussed.
• Future prospects of cyanobacterial PHB in the industry and research are discussed.

The increasing effect of non-degradable plastic wastes is a growing concern. As an alternative, researches are being attempted from living resource to produce bio plastics on the basis of their biodegradability. Due to their cost effect nature, now the scientists are searching an alternative resource like photoautotrophic cyanobacteria. In this review the promising importance and growing awareness of using cyanobacteria as PHB resource are being reported. Many publications evidenced that various cyanobacterial species accumulate intracellular poly-β-hydroxybutyrate granules as energy and carbon reserves inside their cells when they are in stress conditions. PHB is biodegradable, environmental friendly and biocompatible thermoplastics. Varying in toughness and flexibility, depending on their formulation, they can be used in various ways similar to many non-biodegradable petrochemical plastics currently in use. Promising strategies involve genetic engineering of microorganisms to introduce production pathways are being investigated for the past two decades. Such kind of researches focusing on the use of alternative substrates, novel extraction methods, genetically enhanced species and mixed cultures with a view to make PHB from cyanobacteria (blue green algae) more commercially attractive are presented and discussed.