Culture Medium Formulations for High-Cell-Density Starter Cultures
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Solution Overview
Problem
Traditional liquid starter cultures have a short shelf-life and limited cell concentration, leading to high volumes required for industrial production and inferior product quality, while freeze-dried and frozen cultures have poor adaptability and sensory characteristics.
Innovation Solution
Incorporating a suitable amount of basic neutralizing agents, such as calcium carbonate and potassium monohydrogenphosphate, into the culture medium to maintain pH and increase microbial cell concentration and fermentative activity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional liquid starter cultures are used, then the microbial population has perfect physiological state and can replicate immediately, but the cell concentration is limited and shelf-life is short (maximum 4-5 days)
Solution Approach 1:
The patent changes the chemical composition parameters of the culture medium by adding specific basic substances (ammonia, sodium hydroxide, potassium hydroxide, calcium carbonate, or magnesium oxide) to control and maintain pH levels. This parameter change enables the medium to support much higher cell concentrations (up to 16 times higher than traditional cultures) while maintaining the physiological vitality and immediate replication capability of the microbial population.
2Duration of action of stationary object
If freeze-dried and frozen cultures are used, then shelf-life is extended and volumes are reduced, but cells enter a latency stage (LAG stage) and cannot adapt quickly to culture conditions
Solution Approach 1:
The patent applies preliminary action by maintaining the culture medium at optimal pH levels (above 5.8 for thermophilic cultures) during the production and storage phases. This preliminary pH control preserves the physiological state of cells in liquid cultures, allowing them to remain viable and adaptable without entering latency stages, thus eliminating the need for freeze-drying or freezing while extending shelf-life to at least 7 days at refrigerated temperatures.
3Quantity of substance
If culture production time is extended to increase cell concentration, then more biomass is obtained, but pH decreases due to organic acid production which becomes toxic and blocks metabolic activities
Solution Approach 1:
The patent converts the harmful effect of organic acid production into a beneficial outcome by using the acids as a trigger mechanism. The basic substances added to the medium neutralize the organic acids produced during fermentation, and this neutralization process actually stimulates further bacterial growth and metabolism. The pH decrease from acid production is transformed into a signal that activates the buffering system, which in turn promotes continued biomass accumulation up to 16 times higher concentrations.
Solution Approach 2:
The basic substances (ammonia, sodium hydroxide, potassium hydroxide, calcium carbonate, or magnesium oxide) act as intermediary agents between the toxic organic acids and the bacterial cells. These intermediaries neutralize the harmful acids while maintaining the pH within a range that supports metabolic activities, thereby protecting the cells from toxicity while allowing extended production time and higher biomass accumulation.
4Productivity
If large volumes of traditional liquid cultures are used to achieve sufficient cell concentration, then more starting material can be transformed, but the costs increase and productivity decreases
Solution Approach 1:
The patent achieves a 16-fold increase in cell concentration by changing the pH control parameters of the culture medium through the addition of basic substances. This parameter change allows the production of highly concentrated liquid starter cultures (with at least 10^10 CFU/ml) in the same volume, thereby increasing productivity and reducing the volume of culture needed for industrial applications without compromising the physiological state or immediate replication capability of the cells.
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
The method results in a liquid starter culture with significantly higher cell concentration and fermentative activity, achieving up to 16 times the cell concentration and 16 times the fermentative activity of traditional cultures, with improved product quality and stability.
Implementation Method 1
addition of a suitable amount of at least one basic neutralizing agent... to maintain pH and increase microbial cell concentration and fermentative activity
Implementation Method 2
the production of organic acids through fermentation of the carbon sources during bacterial reproduction
Data Source
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AI summary
The present invention relates to formulations of culture mediums for the industrial development of liquid starter cultures characterized by a larger number of microbial cells per volume unit of fermentation medium than the one of traditional liquid starter cultures, which number can be defined a priori depending on the formulation of said medium.