Microbial PolyHydroxyAlkanoate (PHA) Biopolymers—Intrinsically Natural

Abstract

Global pollution from fossil plastics is one of the top environmental threats of our time. At their end-of-life phase, fossil plastics, through recycling, incineration, and disposal result in microplastic formation, elevated atmospheric CO2 levels, and the pollution of terrestrial and aquatic environments. Current regional, national, and global regulations are centered around banning plastic production and use and/or increasing recycling while ignoring efforts to rapidly replace fossil plastics through the use of alternatives, including those that occur in nature. In particular, this review demonstrates how microbial polyhydroxyalkanoates (PHAs), a class of intrinsically natural polymers, can successfully remedy the fossil and persistent plastic dilemma. PHAs are bio-based, biosynthesized, biocompatible, and biodegradable, and thus, domestically and industrially compostable. Therefore, they are an ideal replacement for the fossil plastics pollution dilemma, providing us with the benefits of fossil plastics and meeting all the requirements of a truly circular economy. PHA biopolyesters are natural and green materials in all stages of their life cycle. This review elaborates how the production, consumption, and end-of-life profile of PHAs are embedded in the current and topical, 12 Principles of Green Chemistry, which constitute the basis for sustainable product manufacturing. The time is right for a paradigm shift in plastic manufacturing, use, and disposal. Humankind needs alternatives to fossil plastics, which, as recalcitrant xenobiotics, contribute to the increasing deterioration of our planet. Natural PHA biopolyesters represent that paradigm shift.

Mechanochemical Degradation of Biopolymers

“…These compounds hold clinical significance across various medical fields, including surgery, therapeutics, and tissue engineering. Traditional processing techniques for the manufacture of polyhydroxyalkanoate medical devices, such as melt-spinning, melt extrusion, or solvent evaporation, and emerging processing techniques, such as 3D printing, computer-aided wet-spinning, laser perforation, and electrospinning, are summarized in recent reviews by Koller and Mukherjee [37,282].…”

“…We review the possible changes based on the most common types of biomolecules and mechanochemical technologies. Not only are the macromolecules produced from biological species but also the chemical transformation of biopolymers or polymers produced from biological resources often considered biopolymers [37,38]. Polymers of bio-based repeating units (lactic acid, caprolactam, polybutylene succinate, etc.)…”

Antimicrobial peptide-functionalized polyhydroxyalkanoate bio-beads as a bactericidal material for water disinfection

“…40 The life cycle of PHA adheres to the principles of green chemistry because neither PHA biosynthesis nor biodegradation generates any waste which needs to be treated, and PHA biopolymers are highly biocompatible; they do not exert any risk to the environment or human health. [41][42][43] Furthermore, PHA-based polymers have been employed in a variety of environmental applications, notably for the removal of cationic dye such as methylene blue 44 and organic micropollutant degradation. 45 One of the most common PHAs is poly(3-hydroxybutyric acid) (PHB), which is synthesized through a biosynthesis pathway involving three enzyme components encoded by phaCAB operon.…”

Rapid Estimation of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Composition Using ATR-FTIR

“…Polyhydroxyalkanoates (PHAs) belong to a wide family of polyesters produced by various microorganisms as an energy storage mechanism, triggered by alternating periods of feast and famine when the cells are fed intermittently [1]. After accumulation, PHAs can be extracted from biomass using different procedures [2][3][4].…”