Retainment of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) Properties from Oil-Fermented Cupriavidus necator Using...

Area of Science:

• Biotechnology and Synthetic Biology
• Polymer Science
• Bioprocess Engineering

Background:

• Engineering *Cupriavidus necator* allows production of polyhydroxyalkanoates (PHAs) from vegetable oils.
• Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (P(3HB-co-3HH)) offers improved properties over poly(3-hydroxybutyrate) (PHB).
• Challenges in PHA recovery include residual oil removal and polymer degradation during extraction.

Purpose of the Study:

• To investigate the impact of ethanol-based defatting on P(3HB-co-3HH) recovery and properties.
• To optimize downstream processing for P(3HB-co-3HH) produced from vegetable oils.
• To assess the efficiency of ethanol in removing residual oil and preventing polymer degradation.

Main Methods:

• Addition of ethanol to cell broth for defatting and improved cell separation.
• Washing microbial cells with ethanol post-extraction.
• Analysis of recovery yield, purity, molecular weight, and elongation at break.

Main Results:

• Ethanol washing increased recovery yield to 95.7% and purity to 83.4%, compared to 87.4% and 76.2% with water.
• Molecular weight was 19% higher with ethanol washing, indicating reduced degradation.
• Elongation at break improved significantly to 241.9 ± 27.0% with ethanol, preserving polymer flexibility.

Conclusions:

• Ethanol-based defatting simplifies P(3HB-co-3HH) recovery from vegetable oils.
• Ethanol washing enhances yield, purity, and preserves crucial mechanical properties.
• This method offers a viable strategy for efficient biopolymer production.