Polyhydroxyalkanoates (PHAs): Biopolymers for Biofuel and Biorefineries

Abstract

Fossil fuels are energy recourses that fulfill most of the world’s energy requirements. However, their production and use cause severe health and environmental problems including global warming and pollution. Consequently, plant and animal-based fuels (also termed as biofuels), such as biogas, biodiesel, and many others, have been introduced as alternatives to fossil fuels. Despite the advantages of biofuels, such as being renewable, environmentally friendly, easy to source, and reducing the dependency on foreign oil, there are several drawbacks of using biofuels including high cost, and other factors discussed in the fuel vs. food debate. Therefore, it is imperative to produce novel biofuels while also developing suitable manufacturing processes that ease the aforementioned problems. Polyhydroxyalkanoates (PHAs) are structurally diverse microbial polyesters synthesized by numerous bacteria. Moreover, this structural diversity allows PHAs to readily undergo methyl esterification and to be used as biofuels, which further extends the application value of PHAs. PHA-based biofuels are similar to biodiesel except for having a high oxygen content and no nitrogen or sulfur. In this article, we review the microbial production of PHAs, biofuel production from PHAs, parameters affecting the production of fuel from PHAs, and PHAs biorefineries. In addition, future work on the production of biofuels from PHAs is also discussed.

Utilization of Polymeric Materials toward Sustainable Biodiesel Industry: A Recent Review

“…The biofuel industry was, and still is, one of the expanding sectors to introduce polymers materials to enhance the properties of fuel products. Polymeric biodiesel was synthesized biologically with the help of micro-organismic activity in presence of polymeric feedstock [ 19 , 20 , 21 , 22 ]. In addition, polymers were composited to reduce the higher content of FFA existed in second-generation feedstock oils.…”

Hydrothermal Liquefaction of Biomass as One of the Most Promising Alternatives for the Synthesis of Advanced Liquid Biofuels: A Review

“…For example, a type of biofuel to have generated interest recently would be those formed from Polyhydroxyalkanoates (PHA), which are structurally diverse microbial polyesters synthesized by numerous bacteria. From this novel substrate, a biofuel is obtained similar to biodiesel, except for it having a high oxygen content and no nitrogen or sulfur [ 3 , 4 ]. Biomass is also presented as one of the most promising sustainable energy sources.…”

Polyhydroxyalkanoate/Antifungal Polyene Formulations with Monomeric Hydroxyalkanoic Acids for Improved Antifungal Efficiency

“…Polyhydroxyalkanoates (PHAs) as biodegradable and bio-based materials have gained much of interest lately in a view of the global plastic waste crisis [ 1 , 2 , 3 ]; however, they also possess unique material properties to meet biomedical application-specific requirements [ 4 , 5 , 6 ]. PHAs are family of natural bacterial biopolyesters composed of a wide variety of hydroxyalkanoates monomers giving them tunable mechanical properties from brittle rigid plastics to gummy elastomers [ 7 ].…”