Aspartic Acid Bioproduction Engineering Service

Aspartic Acid (Aspartate) is a key amino acid used in the food industry (as an ingredient in the sweetener Aspartame), pharmaceuticals, and as a raw material for biodegradable plastics. While chemical synthesis is an option, it produces racemic mixtures and is associated with high pollution . Microbial fermentation offers a sustainable, stereo-specific route, but is hindered by low fermentation yield due to complex metabolic regulation and carbon flux competition in the host strain. Biosynthesis optimization is essential to boost industrial viability.

CD Biosynsis offers a synthetic biology service focused on high-yield Aspartic Acid production in Escherichia coli, a robust and fast-growing host. Our core strategy involves modification of aspartate synthase in Escherichia coli . The key enzyme is Aspartate Aminotransferase (AspA), which catalyzes the conversion of fumarate and ammonia into Aspartic Acid. We subject AspA to rational design and/or directed evolution to increase its catalytic activity (kcat) and reduce feedback inhibition by the final product, ensuring a faster conversion rate. This is coupled with optimization of metabolic flux regulation . We engineer the E. coli host's central carbon metabolism to maximize the supply of fumarate (the direct precursor) by reinforcing the TCA cycle's anaplerotic flux (e.g., overexpression of Pyruvate Carboxylase, PPC) and eliminating competing pathways that consume fumarate and oxaloacetate. This integrated approach aims to deliver a high-titer, high-purity Aspartic Acid, significantly reducing both fermentation time and the environmental footprint associated with chemical methods.

Pain Points

Developing a cost-effective, green Aspartic Acid production route faces these key limitations:

• Low Fermentation Yield: Aspartic Acid is an intermediate metabolite for many amino acids (Lysine, Threonine, Methionine). Flux is easily diverted to these competing pathways , resulting in low final yield.
• High Pollution in Chemical Synthesis: Chemical synthesis uses harsh reagents and yields a racemic mixture (D/L-Aspartic Acid), requiring a costly and polluting resolution step to obtain the active L-form.
• Precursor Supply Bottleneck: The supply of oxaloacetate (OAA) and fumarate from the TCA cycle is tightly regulated, acting as a rate-limiting bottleneck for Aspartic Acid production.
• Feedback Inhibition: The final product, Aspartic Acid, can inhibit key biosynthetic enzymes (like Aspartate Kinase), shutting down the pathway prematurely.

A successful solution must eliminate metabolic leakage and ensure a high, regulated flow of precursors to the final enzymatic step.

Solutions

CD Biosynsis utilizes advanced metabolic and enzyme engineering to optimize Aspartic Acid production in E. coli:

Modification of Aspartate Synthase in E. coli

           

We modify the key enzyme, Aspartate Aminotransferase (AspA) , to remove product feedback inhibition and increase its Vmax for high-rate conversion.

Optimization of Metabolic Flux Regulation

We overexpress Pyruvate Carboxylase (PPC) to enhance the anaplerotic pathway, ensuring a massive supply of OAA and fumarate precursors from pyruvate.

Competing Pathway Deletion

We knock out key genes in the biosynthetic pathways of Lysine, Threonine, and Methionine to eliminate flux leakage from Aspartic Acid to other amino acids.

Product Export Enhancement

We overexpress amino acid exporters in E. coli to efficiently transport Aspartic Acid out of the cell, preventing high intracellular concentrations that could trigger feedback inhibition.

This systematic approach is focused on overcoming both the precursor supply bottleneck and the enzymatic rate limitations.

Advantages

Our Aspartic Acid engineering service is dedicated to pursuing the following production goals:

High Stereo-Purity L-Form

Enzymatic synthesis inherently produces the active L-Aspartic Acid , eliminating the need for costly and polluting racemic resolution.

Dramatically Increased Titer and Yield

Precursor flux optimization and pathway blockage ensure maximum carbon conversion to the final product, solving the low yield issue.

Reduced Environmental Footprint

Fermentation uses renewable resources and is a cleaner process than traditional, high-pressure, high-temperature chemical synthesis. [Image of Cost Reduction Icon]

Enhanced Biocatalyst Robustness

Enzyme engineering of AspA leads to a variant that is less sensitive to operational conditions and product accumulation.

Fast and Scalable Host Icon

E. coli is a well-established, fast-growing host, allowing for rapid and cost-effective scale-up to industrial volumes.

We provide a sustainable and economically competitive biosynthetic platform for L-Aspartic Acid production.

Process

Our Aspartic Acid strain engineering service follows a rigorous, multi-stage research workflow:

• Enzyme Engineering: Use rational design or directed evolution to create and screen Aspartate Aminotransferase (AspA) variants for enhanced kcat and resistance to feedback inhibition .
• Flux Optimization: Overexpress Pyruvate Carboxylase (PPC) or Phosphoenolpyruvate Carboxylase (PPC) to boost the anaplerotic supply of OAA and fumarate.
• Pathway Blockage: Use precise gene editing (e.g., CRISPR) to knock out Aspartate Kinase (Ask) activity that diverts flux to Lysine and Threonine biosynthesis.
• Export Enhancement: Clone and overexpress amino acid exporter genes (e.g., YgaA) to increase the secretion rate of Aspartic Acid into the medium.
• Fermentation Performance Validation: Test the final engineered strain in bench-scale bioreactors to assess Aspartic Acid titer, yield, and purity .
• Result Report Output: Compile a detailed Experimental Report including gene modification data, enzyme characterization, and fermentation metrics (yield, titer, and productivity) , supporting industrial scale-up.

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

Explore the potential for a high-yield, green Aspartic Acid supply. CD Biosynsis provides customized strain and enzyme engineering solutions:

• Detailed Metabolic Flux Analysis Report , demonstrating the successful rerouting of carbon to the OAA/fumarate pool.
• Consultation on optimized pH and ammonia feeding strategies to maintain optimal AspA activity.
• Experimental reports include complete raw data on carbon yield (g Aspartic Acid/g glucose) and L-purity (%) , essential for pharmaceutical and food-grade products.