1,2-Propanediol (1,2-PD) Bioproduction Engineering Service

1,2-Propanediol (1,2-PD) is a versatile chemical used in cosmetics, pharmaceuticals, food additives, and for synthesizing unsaturated polyester resins. Traditional production via petrochemical synthesis relies on non-renewable propylene , and the process often involves high pressure and temperature. While microbial synthesis from glycerol (a crude biodiesel byproduct) offers a sustainable route, a major challenge is poor selectivity , resulting in the co-production of large amounts of unwanted byproducts like ethanol, acetate, and 2,3-butanediol.

CD Biosynsis offers a synthetic biology service focused on establishing a clean, high-yield bioproduction route. Our core strategy involves modification of the glycerol metabolism pathway in Klebsiella (or similar hosts) to enhance carbon flux into the 1,2-PD branch while shutting down competing pathways. This is coupled with the directed evolution of dehydrogenase (e.g., diol dehydratase and propanediol dehydrogenase) to boost catalytic efficiency and improve specificity , ensuring the final product is 1,2-PD with minimal coproducts. This integrated approach aims to deliver a high-titer, high-purity, and cost-effective 1,2-PD product from sustainable glycerol feedstock.

Pain Points

Developing a cost-effective and high-selectivity bioproduction route for 1,2-PD faces these critical limitations:

• Reliance on Propylene: Petrochemical synthesis is unsustainable and subject to volatile oil prices , as it uses petroleum-derived propylene as the main reactant.
• Poor Selectivity in Biosynthesis: The glycerol dissimilation pathway is highly branched, leading to the formation of multiple side products (e.g., lactate, acetate, 2,3-butanediol), which reduce the yield and increase separation costs .
• Cofactor Imbalance: The reduction step requires a constant supply of NADH. An imbalance between NADH regeneration and consumption can stagnate the 1,2-PD synthesis rate .
• Enzyme Sensitivity: Key enzymes, particularly diol dehydratase (DhaB), often require an expensive B12cofactor and are sensitive to oxygen and product inhibition .

A cost-effective solution must streamline the metabolic pathway to ensure high product selectivity.

Solutions

CD Biosynsis utilizes advanced synthetic biology to optimize 1,2-PD production in Klebsiella or engineered E. coli :

Modification of Glycerol Metabolism Pathway in Klebsiella

           

We employ genome editing to knock out competing byproduct pathways (e.g., ethanol, butanediol) and upregulate the key enzymes (DhaB, PD dehydrogenase) to force flux toward 1,2-PD.

Directed Evolution of Dehydrogenase

We perform directed evolution on propanediol dehydrogenase (Pdh) to enhance its catalytic efficiency and specificity for 1,2-PD formation, mitigating side reactions.

Cofactor Engineering for NADH Balance

We modify auxiliary pathways to ensure a stable and sufficient supply of NADH , which is essential for the final reduction step in 1,2-PD synthesis.

Enzyme Stabilization and Cofactor-Free Alternatives

We focus on engineering the host for improved B12metabolism or introducing alternative, B}12$-independent enzyme systems to simplify medium complexity and reduce costs.

This systematic approach is focused on achieving high carbon yield and minimizing the expensive separation of coproducts.

Advantages

Our 1,2-PD engineering service is dedicated to pursuing the following production goals:

High Selectivity and Reduced Byproducts

Pathway streamlining ensures that carbon flux is directed solely to 1,2-PD, leading to a higher purity crude broth .

Sustainable Glycerol Utilization

Uses crude glycerol, a waste stream from biodiesel production, as the sole carbon source, enhancing the sustainability of both industries.

Simplified Downstream Processing

Minimized coproduct formation reduces the number of purification steps required, lowering total manufacturing costs. [Image of Cost Reduction Icon]

High NADH Efficiency

Cofactor engineering ensures the redox balance required for the pathway is maintained optimally, maximizing specific productivity.

High Titer and Productivity

Engineered strains are designed to achieve high product concentrations in the fermenter, improving volumetric productivity.

We provide a biosynthetic platform aimed at maximizing the yield and minimizing the purification cost of sustainable 1,2-PD production.

Process

Our 1,2-PD strain engineering service follows a standardized, iterative research workflow:

• Glycerol Pathway Streamlining: Knock out genes (e.g., aldA, adhE, ldh) responsible for the formation of ethanol, acetate, and lactate byproducts.
• Dehydrogenase Optimization: Perform directed evolution on key dehydrogenases (Pdh) to enhance specific activity and reduce substrate ambiguity, thereby increasing selectivity.
• Cofactor Balance Engineering: Introduce or modify pathways to regenerate NADH efficiently, supporting the high demand of the 1,2-PD synthesis branch.
• Enzyme Stability Improvement: Mutate the diol dehydratase (DhaB) gene or its reactivating enzyme (DhaC) to improve oxygen tolerance or remove the B12dependency.
• Fermentation Performance Validation: Test the final engineered strain in fed-batch fermentation to assess 1,2-PD titer, yield, and purity/selectivity .
• Result Report Output: Compile a detailed Experimental Report including strain modification data, flux analysis, and fermentation metrics (yield, titer, and selectivity) , supporting process transfer.

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

Explore the potential for a high-selectivity, sustainable 1,2-PD supply. CD Biosynsis provides customized strain and enzyme engineering solutions:

• Detailed Metabolic Flux and Selectivity Analysis Report , illustrating the success of byproduct elimination and carbon redirection.
• Consultation on fermentation control strategies optimized for high-density growth and sustained NADH supply.
• Experimental reports include complete raw data on carbon yield (g 1,2-PD}/\text{g glycerol) and product purity , essential for reducing downstream costs.