Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors
Abstract In fed‐batch operated industrial bioreactors, glucose‐limited feeding is commonly applied for optimal control of cell growth and product formation. Still, microbial cells such as yeasts and bacteria are frequently exposed to glucose starvation conditions in poorly mixed zones or far away fr...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2023-01-01
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| Series: | Microbial Biotechnology |
| Online Access: | https://doi.org/10.1111/1751-7915.14188 |
| _version_ | 1797974517348302848 |
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| author | Steven Minden Maria Aniolek Henk Noorman Ralf Takors |
| author_facet | Steven Minden Maria Aniolek Henk Noorman Ralf Takors |
| author_sort | Steven Minden |
| collection | DOAJ |
| description | Abstract In fed‐batch operated industrial bioreactors, glucose‐limited feeding is commonly applied for optimal control of cell growth and product formation. Still, microbial cells such as yeasts and bacteria are frequently exposed to glucose starvation conditions in poorly mixed zones or far away from the feedstock inlet point. Despite its commonness, studies mimicking related stimuli are still underrepresented in scale‐up/scale‐down considerations. This may surprise as the transition from glucose limitation to starvation has the potential to provoke regulatory responses with negative consequences for production performance. In order to shed more light, we performed gene‐expression analysis of Saccharomyces cerevisiae grown in intermittently fed chemostat cultures to study the effect of limitation‐starvation transitions. The resulting glucose concentration gradient was representative for the commercial scale and compelled cells to tolerate about 76 s with sub‐optimal substrate supply. Special attention was paid to the adaptation status of the population by discriminating between first time and repeated entry into the starvation regime. Unprepared cells reacted with a transiently reduced growth rate governed by the general stress response. Yeasts adapted to the dynamic environment by increasing internal growth capacities at the cost of rising maintenance demands by 2.7%. Evidence was found that multiple protein kinase A (PKA) and Snf1‐mediated regulatory circuits were initiated and ramped down still keeping the cells in an adapted trade‐off between growth optimization and down‐regulation of stress response. From this finding, primary engineering guidelines are deduced to optimize both the production host's genetic background and the design of scale‐down experiments. |
| first_indexed | 2024-04-11T04:21:02Z |
| format | Article |
| id | doaj.art-c7e010e723c340e0a14dcc83603e09a1 |
| institution | Directory Open Access Journal |
| issn | 1751-7915 |
| language | English |
| last_indexed | 2024-04-11T04:21:02Z |
| publishDate | 2023-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Microbial Biotechnology |
| spelling | doaj.art-c7e010e723c340e0a14dcc83603e09a12022-12-30T19:17:24ZengWileyMicrobial Biotechnology1751-79152023-01-0116114816810.1111/1751-7915.14188Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactorsSteven Minden0Maria Aniolek1Henk Noorman2Ralf Takors3Institute of Biochemical Engineering University of Stuttgart Stuttgart GermanyInstitute of Biochemical Engineering University of Stuttgart Stuttgart GermanyRoyal DSM Delft The NetherlandsInstitute of Biochemical Engineering University of Stuttgart Stuttgart GermanyAbstract In fed‐batch operated industrial bioreactors, glucose‐limited feeding is commonly applied for optimal control of cell growth and product formation. Still, microbial cells such as yeasts and bacteria are frequently exposed to glucose starvation conditions in poorly mixed zones or far away from the feedstock inlet point. Despite its commonness, studies mimicking related stimuli are still underrepresented in scale‐up/scale‐down considerations. This may surprise as the transition from glucose limitation to starvation has the potential to provoke regulatory responses with negative consequences for production performance. In order to shed more light, we performed gene‐expression analysis of Saccharomyces cerevisiae grown in intermittently fed chemostat cultures to study the effect of limitation‐starvation transitions. The resulting glucose concentration gradient was representative for the commercial scale and compelled cells to tolerate about 76 s with sub‐optimal substrate supply. Special attention was paid to the adaptation status of the population by discriminating between first time and repeated entry into the starvation regime. Unprepared cells reacted with a transiently reduced growth rate governed by the general stress response. Yeasts adapted to the dynamic environment by increasing internal growth capacities at the cost of rising maintenance demands by 2.7%. Evidence was found that multiple protein kinase A (PKA) and Snf1‐mediated regulatory circuits were initiated and ramped down still keeping the cells in an adapted trade‐off between growth optimization and down‐regulation of stress response. From this finding, primary engineering guidelines are deduced to optimize both the production host's genetic background and the design of scale‐down experiments.https://doi.org/10.1111/1751-7915.14188 |
| spellingShingle | Steven Minden Maria Aniolek Henk Noorman Ralf Takors Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors Microbial Biotechnology |
| title | Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| title_full | Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| title_fullStr | Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| title_full_unstemmed | Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| title_short | Performing in spite of starvation: How Saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| title_sort | performing in spite of starvation how saccharomyces cerevisiae maintains robust growth when facing famine zones in industrial bioreactors |
| url | https://doi.org/10.1111/1751-7915.14188 |
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