Polyhydroxybutyrate: A Useful Product of Chlorotic Cyanobacteria

Abstract

Polyhydroxybutyrate (PHB) is a carbon polymer with diverse functions, varying greatly on the organism producing it. This microreview describes the current knowledge about PHB metabolism, structure, and different physiological roles with a special focus on cyanobacteria. Despite the physiological function of PHB in the cyanobacterial phylum still being unknown, these organisms provide the unique opportunity to directly convert atmospheric CO₂ into bioplastic using a solar-based process. Recent research on PHB metabolism in the cyanobacterial model organism <i>Synechocystis</i> revealed a sophisticated control of PHB granule formation. Novel insights about the metabolic background of PHB synthesis resulted in the engineering of the first cyanobacterial superproducer strain.