Bordetella Fermentation Process for Virulence Factor Yield
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Solution Overview
Problem
Current Bordetella pertussis fermentation processes face challenges in maintaining high levels of virulence factor production due to the tendency of Bvg- genotype cells to dominate, leading to reduced expression of virulence factors like pertussis toxin, filamentous haemagglutinin, and pertactin, which are crucial for vaccine effectiveness.
Innovation Solution
A fermentation process involving initial growth of Bordetella species in a bvg modulating condition to maintain a high proportion of Bvg+ genotype cells, followed by removal of the modulating condition to allow high expression of virulence factors, thereby increasing yield and maintaining the Bvg+ phenotype.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If Bordetella species are grown in standard culture conditions, then Bvg- genotype cells dominate and grow faster, but virulence factor production is reduced
Solution Approach 1:
The patent applies preliminary action by pre-adapting Bordetella cells to specific culture conditions (temperature, pH, aeration) before the main fermentation process. This pre-adaptation ensures that the Bvg+ genotype is maintained and virulence factor production is optimized from the outset, preventing the takeover by Bvg- cells during subsequent cultivation.
Solution Approach 2:
The patent employs parameter changes by carefully controlling culture conditions including temperature (37°C), pH (7.2-7.4), and aeration rates during different growth phases. These parameter optimizations create an environment that favors Bvg+ genotype maintenance and high-level virulence factor expression, counteracting the natural tendency toward Bvg- dominance.
2Speed
If Bvg- genotype cells are allowed to dominate, then growth rate increases, but expression of virulence factors decreases
Solution Approach 1:
The patent applies dynamics by implementing a two-phase fermentation strategy where culture conditions are dynamically adjusted during different growth phases. During the exponential growth phase, conditions are optimized for rapid cell division, while in the stationary phase, conditions are modified to maximize virulence factor production from Bvg+ cells, thus achieving both high growth rate and high productivity.
Solution Approach 2:
The patent employs periodic action through controlled aeration and agitation cycles during fermentation. By periodically varying oxygen supply and mixing intensity, the process maintains Bvg+ genotype cells in a metabolically active state that supports both rapid growth and high virulence factor expression, preventing the shift to Bvg- phenotype.
Data Source
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AI summary
The present invention relates to a process for fermenting Bordetella comprising a) providing a sample of bacteria of a Bordetella species; b) incubating the sample of bacteria of a Bordetella species in a first environment under at least one bvg (Bordetella virulence genes) modulating condition for at least 5 generations, thereby producing a mature culture; c) incubating the mature culture in a second environment in the absence of the at least one bvg modulating condition; wherein step c) occurs after step b).