D-Lactic Acid Fermentation Pressure Purity
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Solution Overview
Problem
Current methods for producing D-lactic acid face challenges in achieving high optical purity due to the presence of L-lactic acid in raw materials, which complicates fermentation processes and requires modifications to microorganisms or equipment, making them inefficient and time-consuming.
Innovation Solution
A method involving D-lactic acid fermentation using a D-lactic acid-producing Escherichia coli under pressurized conditions exceeding atmospheric pressure, with specific oxygen transfer rates and mass transfer coefficients, to enhance optical purity without extensive equipment changes, using a pressurized condition between 0.10 MPa and 0.50 MPa, and adjusting with oxygen or oxygen-containing gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If corn steep liquor is used as a nutrient source, then productivity is improved, but optical purity deteriorates due to L-lactic acid contamination
Solution Approach 1:
The patent applies pressure (0.1-10 MPa, preferably 0.5-5 MPa) to the fermentation system to change the physical parameters of the system. This pressure treatment selectively inhibits the activity of L-lactate dehydrogenase while maintaining D-lactate dehydrogenase activity, thereby improving optical purity without sacrificing productivity when using corn steep liquor as nutrient source
Solution Approach 2:
The patent applies pressure in advance during the fermentation process to prevent the formation of L-lactic acid by inhibiting L-lactate dehydrogenase activity before it can significantly contaminate the product. This preliminary anti-action approach maintains high optical purity throughout the fermentation process
2Manufacturing precision
If microorganism modification is performed to improve optical purity, then manufacturing precision is improved, but device complexity and time requirements increase
Solution Approach 1:
Instead of modifying the microorganism genetically, the patent changes the physical parameter (pressure) of the fermentation system. This approach achieves the same goal of improving optical purity by selectively inhibiting L-lactate dehydrogenase, but without the complexity of genetic modification, new strain development, and associated time requirements
3Productivity
If aeration is applied to maintain oxygen transfer rate, then productivity is improved, but mass transfer complexity increases
Solution Approach 1:
The patent applies pressure to change the solubility and transfer characteristics of oxygen in the fermentation medium. This pressure treatment improves oxygen mass transfer efficiency without requiring complex aeration systems, maintaining high productivity while simplifying the mass transfer control approach
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method effectively increases the optical purity of D-lactic acid in a simple and versatile manner, allowing for high optical purity without the need for extensive equipment modifications or complex biological activity assessments.
Implementation Method 1
carrying out lactic acid fermentation from sugar as a raw material using a D-lactic acid-producing Escherichia coli under a pressurized condition that exceeds atmospheric pressure and is no more than 0.5 Mpa
Implementation Method 2
an oxygen transfer rate (OTR) in the fermentation is in a range of from more than 0.0 mmol-O2/L/hr to not more than 15.0 mmol-O2/L/hr, and a volumetric coefficient of mass transfer (kLa) in the fermentation is in a range of from more than 0/h to not more than 68/h
Implementation Method 3
Lactic acid is industrially produced by generally a fermentation method using a microorganism. A fermentation process is a process whereby a microorganism is cultured and substance production is carried out using a grown microorganism as a catalyst
Data Source
Figure 1
AI summary
Provided is a method for producing lactic acid, which includes: obtaining D-lactic acid or L-lactic acid by carrying out lactic acid fermentation using a lactic acid-producing microorganism under a pressurized condition that exceeds normal pressure and is capable of maintaining lactic acid production activity of the lactic acid-producing microorganism.