L-Lactic Acid Bioproduction Engineering Service

L-Lactic Acid (L-LA) is a key building block for polylactic acid (PLA) bioplastics used in packaging and textiles. High-strength, high-performance PLA requires L-LA with extremely high optical purity (>99% L-isomer). The challenge is that fermentation often produces both L- and D-lactic acid isomers (racemic mixture) . Additionally, the low pH required for fermentation inhibits cell growth, limiting yield, and the traditional neutralization method leads to high cost of separation and purification due to salt formation .

CD Biosynsis offers a comprehensive metabolic engineering solution to produce L-LA with high optical purity and efficient fermentation. Our strategy includes: Genetic Engineering: Knockout the D-Lactate Dehydrogenase (D-LDH) gene in the strain to ensure L-isomer purity . This eliminates the formation of the D-isomer. We further employ Engineering Tolerance: Modify cell membranes or introduce Efflux pumps to enhance tolerance to low pH and high product concentration . This enables efficient fermentation without costly base addition. Finally, we consider Host Switching: Utilize robust, non-nutritionally demanding hosts like engineered yeasts (e.g., S. cerevisiae) which naturally tolerate low pH and can utilize a wider range of substrates including xylose and lignocellulosic sugars.

Pain Points

Industrial L-Lactic Acid production faces these key challenges:

• Low Optical Purity and Racemic Mixtures: Many wild-type bacteria possess both L- and D-LDH genes, resulting in a mix of isomers that is unsuitable for high-performance PLA synthesis.
• Low pH Inhibition of Cell Growth: Lactic Acid is an acid. Uncontrolled accumulation decreases the fermentation broth pH, inhibiting microbial growth and productivity at high product titers.
• High Separation Cost due to Neutralization: To counteract pH inhibition, base (e.g., Ca(OH)2) is added, forming calcium lactate salt. Converting this salt back to free L-LA requires acidification and energy-intensive purification steps with gypsum waste generation .
• Substrate Versatility Limitations: Traditional LA producers (Lactobacillus) often require expensive nutrients and cannot utilize common low-cost lignocellulosic sugars (e.g., xylose), increasing raw material costs.

A successful solution must provide high optical purity (>99.5%), high productivity at low pH, and simplified downstream processing.

Solutions

CD Biosynsis utilizes metabolic engineering to optimize L-Lactic Acid production:

D-LDH Gene Knockout for Optical Purity

           

Permanently inactivate the gene encoding D-LDH in the host strain to force 100% production of the L-isomer, meeting PLA standards.

Low pH and Product Tolerance Engineering

We modify cell membrane composition (e.g., fatty acid profile) and introduce Efflux pumps to actively expel lactic acid and maintain internal pH, enabling fermentation at low external pH (pH 3.0).

Host Switching and Substrate Expansion

We utilize robust yeasts (e.g., S. cerevisiae or C. glabrata) naturally tolerant to low pH. We engineer them to utilize low-cost feedstocks (xylose) and lignocellulosic hydrolysates.

Maximize L-Lactate Dehydrogenase Activity (L-LDH)

We overexpress and optimize the L-LDH gene to rapidly convert pyruvate to L-LA, maximizing carbon flux and titer.

This integrated approach solves the purity, pH inhibition, and downstream separation problems simultaneously.

Advantages

Our L-Lactic Acid engineering service is dedicated to pursuing the following production goals:

Ultra-High Optical Purity Icon

D-LDH knockout ensures >99.5% L-LA, meeting the highest standards for PLA synthesis.

Low-pH Fermentation Icon

Tolerance engineering allows production at pH 3.0-3.5, avoiding base neutralization and salt formation.

Simplified Downstream Processing Icon

Low pH fermentation means producing free acid directly , eliminating gypsum waste and complex acidification steps. [Image of Cost Reduction Icon]

Low-Cost Substrate Utilization Icon

Using engineered yeast hosts allows for the efficient use of lignocellulosic hydrolysates (xylose and arabinose) to reduce raw material cost.

High Titer and Productivity Icon

Tolerance engineering and L-LDH optimization leads to high fermentation performance under industrial conditions.

We deliver a bio-based, cost-effective, and environmentally cleaner route for L-Lactic Acid production.

Process

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

• Chiral Purity Control: Knockout the D-LDH gene (or D-LDH coding sequence) in the chosen host (e.g., E. coli or yeast) to ensure L-isomer purity.
• Pathway Flux Maximization: Overexpress the L-LDH gene and delete competing pathways (e.g., Ethanol or Acetic Acid production) to maximize L-LA yield.
• Acid Tolerance Engineering: Engineer membrane composition and introduce Efflux pumps (e.g., LacY or HAC efflux systems) to boost tolerance at pH 3.0-3.5.
• Substrate Range Expansion: Introduce heterologous pathways (e.g., xylose utilization genes) to enable growth and LA production on low-cost lignocellulosic sugars .
• Fermentation and Purity Validation: Validate the engineered strain in fed-batch fermentation at low pH, measuring the final L-LA titer (g/L), yield, and optical purity (HPLC with chiral column) .

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

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

• Detailed Optical Purity Certification Report (>99.5% L-isomer guarantee), essential for PLA polymerization.
• Consultation on low-pH fermentation and downstream acid purification protocols for cost efficiency.
• Experimental reports include complete raw data on final titer, yield, productivity, and tolerance metrics in acidic conditions.