{"title":"Mini Bubble Columns for Miniaturizing Scale‐Down","authors":"Moritz Wild, Ralf Takors","doi":"10.1002/elsc.202400051","DOIUrl":null,"url":null,"abstract":"The successful scale‐up of biotechnological processes from laboratory to industrial scale is crucial for translating innovation to practice. Scale‐down simulators have emerged as indispensable tools in this endeavor, enabling the evaluation of potential hosts’ adaptability to the dynamic conditions encountered in large‐scale fermenters. By simulating these real‐world scenarios, scale‐down simulators facilitate more accurate estimations of host productivity, thereby improving the process of selecting optimal strains for industrial production. Conventional scale‐down systems for detailed intracellular analysis necessitate an elaborate setup comprising interconnected lab‐scale reactors such as stirred tank reactors (STRs) and plug‐flow reactors (PFRs), often proving time‐consuming and resource‐intensive. This work introduces a miniaturized bubble column reactor setup (60 mL working volume), enabling individual and parallel carbon‐limited chemostat fermentations, offering a more efficient and streamlined approach. The industrially relevant organism <jats:italic>Escherichia coli</jats:italic>, chosen as a model organism, is continuously grown and subjected to carbon starvation for 150 s, followed by a return to carbon excess for another 150 s. The cellular response is characterized by the accumulation of the alarmone guanosine pentaphosphate (ppGpp) accompanied by a significant reduction in energy charge, from 0.8 to 0.7, which is rapidly replenished upon reintroduction of carbon availability. Transcriptomic analysis reveals a two‐phase response pattern, with over 200 genes upregulated and downregulated. The initial phase is dominated by the CRP–cAMP‐ and ppGpp‐mediated response to carbon limitation, followed by a shift to stationary phase‐inducing gene expression under the control of stress sigma factors. The system's validity is confirmed through a thorough comparison with a conventional STR/PFR setup. The analysis reveals the potential of the system to effectively reproduce data gathered from conventional STR/PFR setups, showcasing its potential use as a scale‐down simulator integrated in the process of strain development.","PeriodicalId":11678,"journal":{"name":"Engineering in Life Sciences","volume":null,"pages":null},"PeriodicalIF":3.9000,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Engineering in Life Sciences","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1002/elsc.202400051","RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"BIOTECHNOLOGY & APPLIED MICROBIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The successful scale‐up of biotechnological processes from laboratory to industrial scale is crucial for translating innovation to practice. Scale‐down simulators have emerged as indispensable tools in this endeavor, enabling the evaluation of potential hosts’ adaptability to the dynamic conditions encountered in large‐scale fermenters. By simulating these real‐world scenarios, scale‐down simulators facilitate more accurate estimations of host productivity, thereby improving the process of selecting optimal strains for industrial production. Conventional scale‐down systems for detailed intracellular analysis necessitate an elaborate setup comprising interconnected lab‐scale reactors such as stirred tank reactors (STRs) and plug‐flow reactors (PFRs), often proving time‐consuming and resource‐intensive. This work introduces a miniaturized bubble column reactor setup (60 mL working volume), enabling individual and parallel carbon‐limited chemostat fermentations, offering a more efficient and streamlined approach. The industrially relevant organism Escherichia coli, chosen as a model organism, is continuously grown and subjected to carbon starvation for 150 s, followed by a return to carbon excess for another 150 s. The cellular response is characterized by the accumulation of the alarmone guanosine pentaphosphate (ppGpp) accompanied by a significant reduction in energy charge, from 0.8 to 0.7, which is rapidly replenished upon reintroduction of carbon availability. Transcriptomic analysis reveals a two‐phase response pattern, with over 200 genes upregulated and downregulated. The initial phase is dominated by the CRP–cAMP‐ and ppGpp‐mediated response to carbon limitation, followed by a shift to stationary phase‐inducing gene expression under the control of stress sigma factors. The system's validity is confirmed through a thorough comparison with a conventional STR/PFR setup. The analysis reveals the potential of the system to effectively reproduce data gathered from conventional STR/PFR setups, showcasing its potential use as a scale‐down simulator integrated in the process of strain development.
期刊介绍:
Engineering in Life Sciences (ELS) focuses on engineering principles and innovations in life sciences and biotechnology. Life sciences and biotechnology covered in ELS encompass the use of biomolecules (e.g. proteins/enzymes), cells (microbial, plant and mammalian origins) and biomaterials for biosynthesis, biotransformation, cell-based treatment and bio-based solutions in industrial and pharmaceutical biotechnologies as well as in biomedicine. ELS especially aims to promote interdisciplinary collaborations among biologists, biotechnologists and engineers for quantitative understanding and holistic engineering (design-built-test) of biological parts and processes in the different application areas.