Dialysis shake flask for effective screening in fed-batch mode

Bähr, Cornelia; Leuchtle, Bernd; Lehmann, Christian W.; Becker, J. Susanne; Jeude, Markus; Peinemann, Frank; Arbter, René; Büchs, Jochen

doi:10.1016/j.bej.2012.08.012

Cited by 36 publications

(54 citation statements)

References 44 publications

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“…(a) Key features of the RAMOS membrane‐based fed‐batch shake flask. For detailed description please refer to Bähr et al () and Philip et al (). (b) Single component glucose feed resulting in carbon (C)‐limited fed‐batch process.…”

Section: Methodsmentioning

confidence: 99%

“…Nevertheless, the most commonly applied strategy to avoid catabolite repression is the implementation of fed‐batch processes (Maurer, ). An additional advantage of the fed‐batch mode is that overflow metabolism, substrate inhibition, and oxygen limitation are avoided (Bähr et al, ; Jeude et al, ).…”

Section: Introductionmentioning

confidence: 99%

“…The membrane‐based fed‐batch shake flask represents an alternative to the above‐presented systems and was introduced by Bähr et al (). It consists of a centrally located feed reservoir that is connected to a diffusion tip via a flexible tube (Figure S1A).…”

Section: Introductionmentioning

confidence: 99%

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Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Habicher

John

Scholl

et al. 2019

Biotech & Bioengineering

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To overcome catabolite repression, industrial fermentation processes are usually operated in substrate-limited fed-batch mode. Therefore, the implementation of such an operating mode at small scale is crucial to maintain comparable process conditions. In this study, Bacillus licheniformis, a well-known producer of proteases, was cultivated with carbon (glucose)-and nitrogen (ammonium)-limited fed-batch conditions using the previously introduced membrane-based fed-batch shake flasks. A repression of protease production by glucose and ammonium was thus avoided and yields increased 1.5-and 2.1-fold relative to batch, respectively. An elevated feeding rate of glucose caused depletion of ammonium, which was recognizable within the oxygen transfer rate (OTR)signal measured with the Respiration Activity MOnitoring System (RAMOS). Ammonium limitation was prevented by feeding ammonium simultaneously with glucose. The OTR signal clearly indicated the initiation of the fed-batch phase and gave direct feedback on the nutrient release kinetics. Increased feeding rates of glucose and ammonium led to an elevated protease activity without affecting the protease yield (Y P/Glu ). In addition to Y P/Glu , protease yields were determined based on the metabolized amount of oxygenThe results showed that the protease production correlated with the amount of consumed glucose as well as with the amount of consumed oxygen. The membranebased fed-batch shake flask in combination with the RAMOS device is a powerful combination to investigate the effect of substrate-limited fed-batch conditions. K E Y W O R D SBacillus licheniformis, catabolite repression, fed-batch, membrane-based fed-batch shake flask, proteases

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Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Habicher

John

Scholl

et al. 2019

Biotech & Bioengineering

Self Cite

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“…For future experiments at smaller scale, a slow‐release technique could be used to avoid growth‐inhibitory effects of elevated phenylpropenoic acid concentrations. This technique is based on diffusion‐driven substrate release and requires a feed reservoir filled with a concentrated substrate solution . Here, a dialysis membrane separating the reservoir from the E. coli cells enables the diffusion of the substrate into the culture medium .…”

Section: Resultsmentioning

confidence: 99%

“…This technique is based on diffusion‐driven substrate release and requires a feed reservoir filled with a concentrated substrate solution . Here, a dialysis membrane separating the reservoir from the E. coli cells enables the diffusion of the substrate into the culture medium . In principle, this approach could also be used for biotransformations at microtiter‐plate scale …”

Section: Resultsmentioning

confidence: 99%

Microbial Production of Natural and Unnatural Monolignols with Escherichia coli

et al. 2019

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Phenylpropanoids and phenylpropanoid‐derived plant polyphenols find numerous applications in the food and pharmaceutical industries. In recent years, several microbial platform organisms have been engineered towards producing such compounds. However, for the most part, microbial (poly)phenol production is inspired by nature, so naturally occurring compounds have predominantly been produced to date. Here we have taken advantage of the promiscuity of the enzymes involved in phenylpropanoid synthesis and exploited the versatility of an engineered Escherichia coli strain harboring a synthetic monolignol pathway to convert supplemented natural and unnatural phenylpropenoic acids into their corresponding monolignols. The performed biotransformations showed that this strain is able to catalyze the stepwise reduction of chemically interesting unnatural phenylpropenoic acids such as 3,4,5‐trimethoxycinnamic acid, 5‐bromoferulic acid, 2‐nitroferulic acid, and a “bicyclic” p‐coumaric acid derivative, in addition to six naturally occurring phenylpropenoic acids.

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Shake Flask Technology

Winkler

Socher

2014

Encyclopedia of Industrial Biotechnology

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For more than 150 years, shake flasks are used in research and development as reaction chambers for chemical and microbiological reactions. An uncountable number of experiments has been performed in shake flasks—a suitable tool for laboratory scale—and, therefore, a lot of data and knowledge was achieved. Owing to its simple but advantageous design, the shake—also called Erlenmeyer—flask represents an appropriate tool for cultivation of biomass in biotechnological laboratories. Recently, more engineering efforts have been performed to describe conditions in shake flasks such as gas transfer or power consumption. Further innovative approaches were developed to either enable larger shaking systems for production or monitor growth‐related parameters online, and at line. Moreover, disadvantages of this technology such as less regulation and controlling possibilities or limitations in gassing/degassing have to be taken into account. The focus of this article is to give fundamental information about the most important issues in shake flask technology for biotechnological applications. Starting with a short historical introduction, the authors highlight the most commonly used types of different flask and closure types, volumes, etc. Subsequently, functions and the introduction of important shaking‐related parameters such as shaking diameter and shaking frequency are given. Before ending up with the innovative potential of modern investigations concerning this significant technology, advantages and disadvantages of shake flask applications are discussed.

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Dialysis shake flask for effective screening in fed-batch mode

Cited by 36 publications

References 44 publications

Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Introducing substrate limitations to overcome catabolite repression in a protease producing Bacillus licheniformis strain using membrane‐based fed‐batch shake flasks

Microbial Production of Natural and Unnatural Monolignols with Escherichia coli

Shake Flask Technology

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