PolyHydroxyAlkanoate sythases: what is known and what remains to be discovered

PolyHydroxyAlkanoate sythases: what is known and what remains to be discovered

Abstract

PolyHydroxyAlkanoates (PHA), microbial polyesters synthesized by various prokaryotic microorganisms, offer a solution to current challenges in the circular economy. Unlike petrochemical-based synthetic polymers, PHA are suitable for biological recycling offering sustainable, selective, and environmentally friendly plastic end-of-life options. Due to the relatively low substrate specificity of PHA synthase (PhaC) – the enzyme responsible for the synthesis of PHA in microbial cells, prokaryotes can incorporate various monomers into the polymer structure. So far, almost 140 different monomer units have been identified in naturally produced PHA polymers. Therefore, PHA are a very diverse and variable family of polymers because monomer composition significantly influences the material and technological properties of the resulting polymers. So far, four different classes of phaC genes and encoded synthases have been defined 20 years ago. Nevertheless, this classification may not be final as the existence of hitherto undefined classes has been already discussed. Although PHA synthases are present in many prokaryotes all over the world, their correct identification is challenging as the primary structure seems to be insufficient for the automatic identification of PHA-encoding genes and their classification. However, additional techniques considering also tertiary (3D) structure have the potential to bring desirable improvement. In our recent work, we have identified numerous synthases that were unannotated in current databases. We plan to address this limitation in the following 5 years by building a novel database aimed specifically at PHA synthases, bringing their novel classification, and characterizing every class thanks to additional experiments, including exploring the physicochemical properties of produced PHA polymers.

PolyHydroxyAlkanoates (PHA), microbial polyesters synthesized by various prokaryotic microorganisms, offer a solution to current challenges in the circular economy. Unlike petrochemical-based synthetic polymers, PHA are suitable for biological recycling offering sustainable, selective, and environmentally friendly plastic end-of-life options. Due to the relatively low substrate specificity of PHA synthase (PhaC) – the enzyme responsible for the synthesis of PHA in microbial cells, prokaryotes can incorporate various monomers into the polymer structure. So far, almost 140 different monomer units have been identified in naturally produced PHA polymers. Therefore, PHA are a very diverse and variable family of polymers because monomer composition significantly influences the material and technological properties of the resulting polymers. So far, four different classes of phaC genes and encoded synthases have been defined 20 years ago. Nevertheless, this classification may not be final as the existence of hitherto undefined classes has been already discussed. Although PHA synthases are present in many prokaryotes all over the world, their correct identification is challenging as the primary structure seems to be insufficient for the automatic identification of PHA-encoding genes and their classification. However, additional techniques considering also tertiary (3D) structure have the potential to bring desirable improvement. In our recent work, we have identified numerous synthases that were unannotated in current databases. We plan to address this limitation in the following 5 years by building a novel database aimed specifically at PHA synthases, bringing their novel classification, and characterizing every class thanks to additional experiments, including exploring the physicochemical properties of produced PHA polymers.

SEDLÁŘ, K.; BUCHTÍKOVÁ, I.; OBRUČA, S.

15.04.2025

978-80-88307-24-2

12th International Conference on Chemical Technology book of abstracts

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