Production of polyhydroxybutyrate (PHB) in Scenedesmus acutus using a low-cost substrate.

The importance of conventional plastics is undeniable; however, their non-biodegradability makes them one of the biggest environmental problems. Among the alternatives to mitigate environmental damages, the production of polyhydroxyalkanoates (PHB) provides a biodegradable solution, making them accessible to a wide variety of applications. In general, biopolymers accumulate as energy and carbon storage material in microorganisms such as bacteria and microalgae. In the present study, the impact of different sources like carbon, glucose, nitrogen and sodium was tested on the production of PHB in the cultures of the microalgae Scenedesmus acutus. To evaluate the effect of the variables, a fractional Taguchi experimental design was devised and executed, thus, 16 experimental runs and 3 replicas in each treatment were considered. Results showed calculated concentrations of the biopolymer in a range from 7.5 to 24.7% w/w of dry weight. Additionally, the PHB was identified by spectroscopic and thermogravimetric analysis. Statistical analysis was performed, showing differences in biomass production, PHB concentration in g L