High-cell-density fed-batch strategy to manufacture tailor-made P(HB-co-HHx) by engineered Ralstonia eutropha at...

Area of Science:

• Biotechnology and Bioprocess Engineering
• Polymer Science
• Sustainable Materials

Background:

• The transition to a bioeconomy necessitates cost-effective bioprocesses for bulk material production.
• Polyhydroxyalkanoates (PHAs) are biobased and biodegradable plastics with tunable properties.
• Poly(hydroxybutyrate-co-hydroxyhexanoate) (P(HB-co-HHx)) offers desirable material characteristics modulated by monomer composition.

Purpose of the Study:

• To develop a high-cell-density fed-batch strategy for producing P(HB-co-HHx) with controlled composition.
• To scale up the production process from laboratory to pilot scale.
• To enable the kilogram-scale production of PHA bioplastics with specific material properties.

Main Methods:

• Utilized a high-cell-density fed-batch strategy with fructose and canola oil mixtures.
• Employed Ralstonia eutropha Re2058/pCB113 for P(HB-co-HHx) production.
• Scaled the process from 1-L laboratory to 150-L pilot scale.

Main Results:

• Achieved cell densities exceeding 100 g/L.
• Produced PHA containing 70-80 wt% polymer.
• Tuned HHx content in the range of 9.0-14.6 mol%.
• Reached productivities up to 1.5 g/L/h.
• Demonstrated tailor-made P(HB-co-HHx) production at an industrially relevant scale.

Conclusions:

• The developed fed-batch strategy enables the tailor-made production of P(HB-co-HHx) at an industrially relevant scale.
• This approach facilitates kilogram-scale production of PHA bioplastics with defined material properties.
• The strategy supports the commercialization of PHA as a sustainable alternative to conventional plastics.