Lactococcus lactis Fermentation Yield via Nucleic Acid Precursors
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Solution Overview
Problem
Current methods for producing lactic acid bacteria (LAB) starter cultures face challenges in achieving high biomass yields during fermentation, particularly at high Optical Density conditions, due to the energy and protein burdens associated with synthesizing biosynthetic enzymes and the limited effectiveness of compounds involved in nucleic acid biosynthesis in enhancing yields.
Innovation Solution
Incorporating yield-enhancing agents such as purine bases, pyrimidine bases, nucleosides, nucleotides, and their derivatives into the culture medium at concentrations of at least 1 μM to ensure their presence throughout fermentation, thereby reducing the need for de novo enzyme synthesis and increasing biomass yield.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If compounds involved in nucleic acid biosynthesis are added to the culture medium, then the biomass yield of LAB is improved, but the energy burden on the cell for synthesizing biosynthetic enzymes increases
Solution Approach 1:
The culture medium is pre-supplemented with compounds involved in nucleic acid biosynthesis (purines, pyrimidines, nucleosides, nucleotides) before the fermentation process begins. This preliminary provision of essential building blocks allows the bacteria to immediately utilize these compounds during growth without needing to synthesize them de novo, thereby reducing the energy burden while maintaining high biomass yield.
2Productivity
If the concentration of propagated cells is increased to achieve high Optical Density, then the productivity is improved, but the demands on fermentation conditions and medium composition increase
Solution Approach 1:
The chemical composition of the fermentation medium is modified by adding specific compounds involved in nucleic acid biosynthesis. This parameter change in medium composition enables the bacteria to achieve high cell concentrations and Optical Density values without requiring complex or extreme fermentation conditions, thereby simplifying the overall process while maintaining high productivity.
3Ease of manufacture
If complex undefined fermentation media are used to support cell viability, then the ease of manufacture is improved, but the biomass yield is limited
Solution Approach 1:
The fermentation medium combines complex undefined components (such as yeast extract, cornstarch, whey protein) with specific pure chemical compounds involved in nucleic acid biosynthesis. This composite approach maintains the ease of manufacture associated with complex media while adding targeted nutritional supplements that enable significantly higher biomass yields, thus resolving the contradiction between ease of manufacture and productivity.
Data Source
AI summary
Microbial starter cultures. More specifically, a method for preparing a microbial starter culture wherein the microorganism is inoculated in a culture medium comprising at least one 5 yield enhancing agent selected from the group consisting of a purine base, a pyrimidine base, a nucleoside and a nucleotide. Such microbial starter cultures are useful in the manufacturing of food, feed and pharmaceutical products.