Structural Insights Into Biopolymer PHA Granular Phasins: Comparison Analysis & Function Validation

- PHA functions:

• substitute for petroleum derived thermoplastics (petrochemical plastics for 'white pollution', environmentally unfriendly)
• as scaffold/implant biomaterials in tissue engineering

- monomers of PHA depend on:

• type of PHA producing bacterium
• growth conditions

- Typical PHAs:

a) PHB:

• c4 monomer
• SCL
• homopolymer that is synthesized from Wautersia eutropha strain H16

b) poly (3-hydroxybutyrate-co-3-hydroxyhexanoate)

• PHBHHX
• C4 & C6 monomers
• copolymer of SCL-MCL PHA
• heteropolymer from Aeromonas hydrophila strain 4AK4

- Native PHA were accumulated as intracellular granules (inclusion bodies) in vivo
- PHA granules were found enveloped by various granule associated proteins
- Non-enzymatic structural proteins associated to PHA granules are called: PHA granular phasins
- low phasin = low PHA content = PHA number

Fig. 1 Summarized types of PHA envelopes

Fig.2 Summarized phasins' functions