Poly(3-hydroxybutyrate) PHB Engineering Service

Poly(3-hydroxybutyrate) (PHB) is a natural, biodegradable polymer belonging to the Polyhydroxyalkanoates (PHAs) family, promising for Bioplastics/Medical applications. However, its commercial use is limited by several drawbacks: PHB is typically brittle; production yield is low, and fermentation cost is high. These issues prevent PHB from competing effectively with petrochemical plastics.

CD Biosynsis employs comprehensive engineering strategies to address these flaws: Genetic Engineering: Knockout PHA Depolymerase genes and TCA cycle genes. This maximizes accumulation and shunts carbon flux towards polymer synthesis. Furthermore, we Introduce Fatty Acid pathway modification to produce PHBV (co-polymer) for improved flexibility. This creates a more versatile bioplastic. Finally, we implement Host Engineering: Utilize Cyanobacteria for CO2 as a cheap carbon source. This phototrophic route lowers feedstock costs dramatically, making PHB production economically viable and highly sustainable.

Pain Points

Commercialization of PHB faces these key technical and economic barriers:

• Material Brittleness: Pure PHB has a high crystallinity that makes it brittle and difficult to process, limiting its use as a flexible bioplastic.
• High Feedstock Cost: Traditional PHB production relies on expensive carbon sources e.g. glucose or molasses, which dominates the overall fermentation cost.
• Low Yield in Wild Strains: Native microbes synthesize PHB slowly and often degrade it using intracellular depolymerases, resulting in poor yields.
• Batch Process Inefficiency: PHB accumulation is often limited by the need for a two-stage process requiring nutrient limitation e.g. nitrogen starvation to induce polymer synthesis.

Genetic and Host Engineering is crucial to improve properties and economics.

Solutions

CD Biosynsis implements a multi-level strategy for enhanced PHB and PHBV production:

Flux Maximization via Knockouts

           

We knockout genes responsible for PHA depolymerization and competing pathways e.g. TCA cycle to drive maximum carbon flow to PHB.

PHBV Co-Polymer Modification

We introduce genes from the fatty acid oxidation pathway to incorporate HV monomers e.g. 3-hydroxyvalerate HV to produce flexible PHBV.

Phototrophic Carbon Source Utilization

We engineer Cyanobacteria hosts to utilize low-cost CO2 as the primary carbon source for PHB synthesis, eliminating sugar cost.

Continuous Production Optimization

We design a continuous fermentation system that couples growth and PHB production to avoid costly two-stage batch processes.

Our solution delivers cost-competitive, flexible, and highly sustainable bioplastics.

Advantages

Our PHB/PHBV engineering service offers these core benefits:

Dramatically Reduced Cost

Using CO2 as a feedstock in cyanobacteria cuts the biggest cost component sugar, making PHB competitive with petroleum plastics.

Improved Bioplastic Flexibility

Producing the PHBV co-polymer reduces brittleness and improves ductility, expanding its use in packaging and films.

Increased Titer and Yield

Genetic knockouts and flux shunting maximize the microbe's efficiency in converting carbon to polymer, boosting overall productivity.

Superior Sustainability

The phototrophic route is carbon negative or neutral, as it utilizes waste CO2 and sunlight, offering the cleanest possible production method.

Reduced Processing Time

Coupling growth and production in a single optimized step eliminates the need for a costly and time-consuming nutrient starvation phase.

We provide a cost-effective, sustainable, and high-performance PHB bioplastic solution.

Process

Our PHB/PHBV engineering service follows a rigorous, multi-stage research workflow:

• Genetic Knockout Strategy: Design and execute the deletion of intracellular depolymerase phaZ and select TCA cycle genes to enhance polymer accumulation.
• PHBV Pathway Introduction: Introduce and optimize the expression of key enzymes e.g. PhaC polymerase and thiolase to enable HV monomer incorporation.
• Cyanobacteria Host Tuning: Metabolically engineer Synechocystis or Synechococcus to efficiently fix CO2 and shunt carbon into the PHB pathway.
• Photobioreactor Optimization: Develop optimal light, CO2, and nutrient feeding strategies for high-density and high-productivity fermentation.
• Polymer Characterization: Analyze final PHB/PHBV product for molecular weight, thermal properties e.g. Tg, Tm and HV content using NMR and DSC.

Technical communication is maintained throughout the process, focusing on timely feedback regarding yield and product stability attributes.

Explore the potential for a cost-competitive, flexible, PHB bioplastic supply. CD Biosynsis provides customized strain and process engineering solutions:

• Detailed PHB/PHBV Titer, Yield, and Polymer Composition Reports g/L, percent CDW, HV content.
• Consultation on processing parameters e.g. extrusion and molding for the engineered PHBV copolymer.
• Experimental reports include complete raw data on metabolic flux analysis, photobioreactor performance, and PHA granule analysis.