Glutamic Acid Bioproduction Engineering Service

Glutamic Acid is the second largest amino acid produced globally, primarily used as a flavor enhancer (MSG) and in pharmaceuticals. Industrial production using Corynebacterium glutamicum faces challenges: low acid production rate in fermentation can result from metabolic bottlenecks in the TCA cycle and feedback inhibition, leading to extended, high-cost batch cycles. Furthermore, the inherent difficulty of exporting the product and product degradation contribute to insufficient extraction yield from the fermentation broth, increasing downstream costs. Biosynthesis optimization, particularly focusing on the flux and export mechanisms, is key to competitive production.

CD Biosynsis offers a synthetic biology service focused on highly efficient Glutamic Acid production in Corynebacterium glutamicum. Our core strategy involves modification of cell membrane permeability in Corynebacterium glutamicum . We introduce targeted mutations or utilize chemical treatments (e.g., surfactants, penicillin) to temporarily increase the permeability of the cell membrane. This facilitates the efficient, high-flux export of Glutamic Acid from the cytoplasm to the medium, preventing feedback inhibition and maximizing the external concentration. This is coupled with overexpression of citrate synthase . Citrate Synthase (CS) catalyzes the critical first step of the TCA cycle, converting oxaloacetate and acetyl-CoA into citrate, a reaction that must be controlled to redirect the pathway toward Glutamic Acid production. While the pathway normally flows to Glutamate, overexpression of CS in a TCA cycle-blocked strain can be used to re-balance the TCA intermediate pool, or, in concert with pathway modification, to pull carbon flux towards alpha-ketoglutarate, the direct precursor to Glutamate. This integrated approach aims to deliver high-titer Glutamic Acid, reducing both fermentation time and downstream purification expenses.

Pain Points

Developing a cost-effective Glutamic Acid production route faces these key limitations:

• Low Acid Production Rate in Fermentation: Flux through the TCA cycle is tightly regulated, and high intracellular Glutamic Acid concentrations lead to feedback inhibition , stalling the production rate.
• Insufficient Extraction Yield: While C. glutamicum produces Glutamate, the final yield is limited by inefficient or expensive separation from cell debris and other metabolites, resulting in high purification loss and cost.
• Metabolic Leakage: Carbon flux can leak to undesirable by-products (e.g., succinate, lactate, and acetate), reducing the theoretical carbon yield toward Glutamic Acid.
• GABA Shunt Competition: The GABA (gamma-Aminobutyric Acid) shunt can consume Glutamate, acting as a competing pathway and lowering the final product titer.

A successful solution must maximize precursor flow, control the TCA cycle, and optimize product export efficiency.

Solutions

CD Biosynsis utilizes advanced metabolic engineering to optimize Glutamic Acid production in C. glutamicum:

Modification of Cell Membrane Permeability in C. glutamicum

           

We overexpress the native Glutamate exporter gene (YddG or similar) or engineer the cell membrane structure to dramatically increase the rate of Glutamic Acid secretion, preventing intracellular accumulation and feedback inhibition.

Overexpression of Citrate Synthase

We selectively overexpress a deregulated Citrate Synthase variant (CS) to pull carbon flux into the TCA cycle towards alpha-ketoglutarate, the immediate precursor to Glutamate, maximizing the production rate.

GABA Shunt Deletion

We delete or downregulate genes involved in the GABA shunt to eliminate Glutamate consumption for GABA synthesis, ensuring maximum product accumulation.

Ammonium Assimilation Pathway Optimization

We fine-tune the expression of Glutamate Dehydrogenase (GDH) to ensure an efficient supply of ammonia and NADPH for the final conversion of alpha-ketoglutarate to Glutamate.

This systematic approach is focused on optimizing both the metabolic flux towards the precursor and the export efficiency of the final product.

Advantages

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

High Fermentation Titer and Productivity

Enhanced precursor supply and product export lead to a faster production rate and higher final concentration , solving the low yield issue.

Reduced Downstream Processing Burden

Higher titer and cleaner broth from efficient export simplify purification, lowering the total extraction cost . [Image of Cost Reduction Icon]

Minimized By-product Formation

Deletion of competing pathways ensures that carbon is efficiently directed to Glutamic Acid, boosting the theoretical yield.

Consistent Production Reliability

Genetic modification of the exporter is more reliable and controllable than relying on traditional chemical induction (e.g., biotin limitation or surfactants) for cell permeability.

High Purity Output

Optimization of GDH ensures the product is the desired L-Glutamic Acid enantiomer, meeting food and pharmaceutical standards.

We provide a specialized metabolic engineering platform aimed at optimizing the yield and cost-effectiveness of Glutamic Acid production.

Process

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

• TCA Cycle Balancing: Overexpress deregulated Citrate Synthase (CS) and knock out competing TCA bypass pathways (e.g., sucD) to maximize alpha-ketoglutarate availability.
• Exporter Engineering: Overexpress the YddG transporter or genetically modify the cell wall synthesis pathway to permanently enhance membrane permeability and Glutamate secretion.
• Competing Pathway Deletion: Use precise gene editing (e.g., CRISPR) to delete GABA shunt genes and other by-product forming pathways to eliminate carbon loss.
• Fermentation Process Development: Optimize media composition and pH control (e.g., NH3 feeding strategy) to maintain high GDH activity and suppress by-product formation .
• Fermentation Performance Validation: Test the final engineered strain in bench-scale bioreactors to assess Glutamic Acid titer, yield, and by-product profile .
• Result Report Output: Compile a detailed Experimental Report including gene modification data, exporter efficiency measurements, and fermentation metrics (yield, titer, and productivity) , supporting commercial scale-up.

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

Explore the potential for a high-titer, cost-effective Glutamic Acid supply. CD Biosynsis provides customized strain and process engineering solutions:

• Detailed Excretion Rate and Titer Analysis Report , demonstrating the success of membrane permeability modification and CS overexpression.
• Consultation on optimized pH and NH3 feeding strategies to reduce operational costs.
• Experimental reports include complete raw data on carbon yield (g Glutamate/g sugar) and product purity (%) , essential for industrial application.