Engineering of PHA Synthase for Sustainable Bioplastics Production

Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible polyesters synthesized by microorganisms, positioning them as a promising, eco-friendly alternative to conventional petroleum-based plastics. The core enzyme for their biosynthesis is PHA Synthase (PhaC). However, the commercial viability of PHA is hampered by key technical challenges: low conversion yield from cheap carbon sources (e.g., typically below 60%), high production costs (approx. $8-10/kg), and a lack of precise control over the polymer's molecular weight, chain length, and monomer composition.

Our specialized enzyme optimization services are focused on creating PHA Synthase variants with superior efficiency and controllability. Our core objectives include: enhancing enzyme affinity toward low-cost feedstocks; improving the overall bioconversion yield; and achieving precise control over the resulting polymer's physical properties for targeted applications. Consult with our experts to design a customized strategy that accelerates the sustainable, cost-effective production of next-generation bioplastics.

Get a Quote

Challenges Engineering Focus Technology Platforms Project Flow FAQ

Challenges in Commercial PHA Synthase Performance

The large-scale and cost-effective production of PHA bioplastics is limited by the following technical barriers in the enzyme:

Low Conversion Yield: Inefficient uptake and conversion of cheap, unconventional carbon sources (e.g., waste cooking oil, industrial byproducts, methane) into the PHA monomer precursors, leading to yields often below 60%.
High Production Cost: The high cost ($8-10/kg) is partly due to the necessity of using expensive co-substrates or inefficient substrate conversion, hindering market competitiveness against conventional plastics.
Polymer Control Difficulty: The inability to precisely regulate the polymerization process, resulting in broad molecular weight distribution and unpredictable monomer incorporation ratios.
Thermal Instability: PHA Synthase can be prone to denaturation during the production process, especially in systems optimized for high-temperature fermentation or high monomer concentration.

Our engineering platforms are dedicated to resolving these complex yield, cost, and polymer control challenges.

Engineering Focus: Substrate Affinity and Polymer Control

We apply integrated protein engineering strategies to enhance your target PHA Synthase (PhaC):

Enhanced Substrate Specificity

Using Directed Evolution to increase the enzyme's affinity and specificity for low-cost and unconventional feedstocks (e.g., waste glycerol, short-chain fatty acids).

Increased Conversion Yield

Optimizing catalytic efficiency and turnover rate (kcat) to maximize the conversion of intracellular monomer precursors into the final PHA polymer, improving overall yield.

Precise Polymer Composition Control

Implementing Rational Design of the active site to precisely influence the ratio of different monomers incorporated, tailoring the final polymer's properties (e.g., flexibility, melt temperature).

Enhanced Thermal and Chemical Stability

Maximizing the enzyme's thermal stability to withstand high fermentation temperatures and ensuring long-term activity under varying process conditions.

Our experts are ready to apply these integrated capabilities to achieve next-generation PHA Synthases with higher yield and customizable polymer products.

Technology Platforms for PHA Synthase Engineering

We leverage a suite of cutting-edge platforms to deliver highly functional enzyme variants:

AI-Guided Discovery of High-Yield Variants

Using AI-guided metagenomic analysis and deep learning sequence mining to discover naturally high-performing PHA Synthase starting points.

Directed Evolution for Substrate Specificity

We utilize HTS platforms optimized for screening variants with enhanced affinity for target low-cost feedstocks (e.g., waste oil).

Rational Design for Polymer Control

Using structural modeling and rational design to engineer mutations that influence the binding and incorporation of specific monomers, controlling polymer composition.

Polymer Composition and Yield Profiling

We offer full characterization services, including GC-MS or NMR analysis of the resulting PHA polymer to measure composition, molecular weight, and yield.

Integrated Enzyme Production and Scale-Up

Specialized custom production services to achieve high yield and purity of the engineered PhaC, suitable for incorporation into microbial hosts for large-scale bioplastics manufacturing.

Partner with us to harness these platforms for next-generation, cost-effective PHA production performance.

Project Flow: PHA Synthase Optimization Workflow

Our enzyme optimization projects follow a flexible, milestone-driven workflow:

Consultation and Goal Definition: Initial discussion to define the cost reduction target (e.g., target PHA production cost), the minimum required yield, and the desired polymer composition/molecular weight.
Design Strategy Proposal: We propose a tailored strategy involving Rational Design (for composition control) and/or Directed Evolution (for substrate affinity/yield), outlining the predicted timeframe.
Library Construction and Screening: We execute mutagenesis and employ HTS platforms using target low-cost carbon sources and high-throughput PHA detection methods (e.g., Nile Red staining) to identify lead variants.
Iterative Optimization & Profiling: Successive rounds of evolution focus on maximizing both conversion yield and the precision of monomer incorporation, followed by detailed polymer analysis.
Final Deliverables: Delivery of the final PHA Synthase variant, the expression strain, and detailed reports on kinetic data, thermal stability, polymer composition, and target yield achievement.

Technical communication is maintained throughout the project. We encourage potential clients to initiate a consultation to discuss their specific bioplastic production challenges and explore how our technologies can achieve superior performance and cost efficiency.

We provide comprehensive support, including:

Detailed Kinetic Data, Thermal Stability Profiles, and Residual Activity Reports in fermentation conditions.
Analytical reports including polymer composition (GC-MS/NMR) and molecular weight (GPC/SEC) data.
Experimental reports include complete raw data on mutagenesis libraries, HTS screening results, and final yield confirmation.

FAQ Frequently Asked Questions

Still have questions?

How do you improve the yield from low-cost carbon sources?

We use Directed Evolution combined with cell-based screening to select for PHA Synthase variants that have a higher uptake rate and catalytic efficiency toward the low-cost precursor monomers derived from the feedstock.

What is the main strategy for controlling polymer composition (e.g., copolymer ratios)?

The primary strategy is Rational Design of the enzyme's active site and substrate tunnel. By modifying key residues, we can influence the enzyme's preference and binding affinity for specific types of monomer precursors (e.g., 3-hydroxybutyrate vs. 3-hydroxyhexanoate), achieving precise ratio control.

How do you increase the thermal stability of PHA Synthase?

We employ stability engineering by introducing stabilizing mutations (e.g., enhanced salt bridges or hydrophobic packing) identified through computational modeling to increase the enzyme's melting temperature and half-life at elevated fermentation temperatures.

What methods are used to analyze the synthesized PHA polymer?

We use analytical techniques such as Gas Chromatography–Mass Spectrometry (GC-MS) or Nuclear Magnetic Resonance (NMR) to quantify the monomer composition and Gel Permeation Chromatography (GPC) or Size Exclusion Chromatography (SEC) to determine the molecular weight and distribution of the resulting PHA polymer.