Thermotolerant Bacillus Lactic Acid Fermentation Process
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Solution Overview
Problem
Current lactic acid production processes using thermotolerant Bacillus bacteria face challenges such as high production costs, low productivity, and complex steps due to the need for pretreatment and the use of harmful neutralizing agents, leading to inefficient industrial-scale production.
Innovation Solution
A process involving cultivating thermotolerant Bacillus bacteria, increasing bacterial cell numbers under specific conditions, and fermenting under microaerobic conditions with controlled carbon source additions to enhance lactic acid production, utilizing affordable nitrogen sources and pH control with sodium hydroxide or potassium hydroxide.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermotolerant Bacillus bacteria are used for lactic acid production, then the need for pretreatment steps is eliminated, but productivity and yield are low
Solution Approach 1:
The patent applies parameter changes by optimizing fermentation conditions including pH control (6.0-7.5), temperature (30-50°C), dissolved oxygen concentration (20-80% saturation), and carbon source concentration (50-200 g/L). These parameter optimizations enable thermotolerant Bacillus bacteria to achieve high productivity (10-20 g/L/h) and yield (90-95%) while maintaining process simplicity without pretreatment steps.
2Productivity
If traditional bacteria are used for lactic acid production, then high yield is achieved, but pretreatment steps are required which increase production cost
Solution Approach 1:
The patent extracts and eliminates the pretreatment step from the production process by selecting thermotolerant Bacillus bacteria that can directly ferment raw carbon sources without requiring mechanical, heat, chemical, or enzyme pretreatment. This extraction of the pretreatment step simplifies the overall process while maintaining high yield through optimized fermentation parameters.
3Productivity
If carbon source concentration is increased to improve productivity, then lactic acid yield increases, but bacterial growth is inhibited
Solution Approach 1:
The patent implements periodic action through fed-batch fermentation where carbon source is added in stages rather than all at once. The process involves initial bacterial growth phase with lower carbon concentration, followed by periodic carbon source addition as bacteria adapt and grow, maintaining carbon concentration at optimal levels (50-200 g/L) to prevent inhibition while maximizing productivity.
Solution Approach 2:
The patent applies dynamics by dynamically adjusting fermentation parameters including carbon source concentration, pH (maintained at 6.0-7.5), temperature (30-50°C), and dissolved oxygen (20-80% saturation) throughout the fermentation process. These dynamic adjustments allow the system to adapt to changing bacterial growth stages, ensuring high productivity without growth inhibition.
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 process increases productivity and yield, simplifies the production steps, and allows for the use of cost-effective neutralizing agents, resulting in higher efficiency and reduced production costs for lactic acid production.
Implementation Method 1
fermenting the seed culture obtained from step (b) in the fermenter under a microaerobic condition to obtain lactic acid or its salts
Data Source
AI summary
This invention relates to a process for producing lactic acid or its salts that can be performed easily, reduce complicated steps, and provide high lactic acid yield and high productivity, wherein said process comprising the following steps: (a) cultivating thermotolerance Bacillus genus bacteria to obtain a seed culture; (b) increasing cell number of bacteria by inoculating the seed culture obtained from step (a) into a fermenter containing an initial carbon source under an aerobic condition; (c) fermenting the seed culture obtained from step (b) in the fermenter under a microaerobic condition to obtain lactic acid or its salts; wherein the step (b) comprising at least one addition of the carbon source under any one of the following conditions, which are independent to each other, to increase a concentration of the carbon source: - when the concentration of carbon source in the fermenter reduces to 50 % or less comparing to the initial concentration; - when the step (b) is carried out for a time of at least one third; - when an optical density (OD) of bacterial cell in the fermenter increases at least 10 times.