scholarly journals Parallelized microscale fed-batch cultivation in online-monitored microtiter plates: implications of media composition and feed strategies for process design and performance

2019 ◽  
Vol 47 (1) ◽  
pp. 35-47
Author(s):  
Holger Morschett ◽  
Roman Jansen ◽  
Christian Neuendorf ◽  
Matthias Moch ◽  
Wolfgang Wiechert ◽  
...  
Keyword(s):  
Ph Control ◽  
Batch Cultivation ◽  
Fed Batch ◽  
Batch Mode ◽  
Microtiter Plates ◽  
Exponential Feeding ◽  
Media Component ◽  
Improved Performance ◽  
And Performance ◽  
Biological Performance

Abstract Limited throughput represents a substantial drawback during bioprocess development. In recent years, several commercial microbioreactor systems have emerged featuring parallelized experimentation with optical monitoring. However, many devices remain limited to batch mode and do not represent the fed-batch strategy typically applied on an industrial scale. A workflow for 32-fold parallelized microscale cultivation of protein secreting Corynebacterium glutamicum in microtiter plates incorporating online monitoring, pH control and feeding was developed and validated. Critical interference of the essential media component protocatechuic acid with pH measurement was revealed, but was effectively resolved by 80% concentration reduction without affecting biological performance. Microfluidic pH control and feeding (pulsed, constant and exponential) were successfully implemented: Whereas pH control improved performance only slightly, feeding revealed a much higher optimization potential. Exponential feeding with µ = 0.1 h−1 resulted in the highest product titers. In contrast, other performance indicators such as biomass-specific or volumetric productivity resulted in different optimal feeding regimes.

scholarly journals Screening for optimal protease producing Bacillus licheniformis strains with polymer-based controlled-release fed-batch microtiter plates

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tobias Habicher ◽  
Tobias Klein ◽  
Jacqueline Becker ◽  
Andreas Daub ◽  
Jochen Büchs
Keyword(s):  
Controlled Release ◽  
Bacillus Licheniformis ◽  
Protease Activity ◽  
Microtiter Plate ◽  
Fed Batch ◽  
Batch Mode ◽  
Screening Process ◽  
Microtiter Plates ◽  
Batch Fermenter ◽  
Production Conditions

Abstract Background Substrate-limited fed-batch conditions have the favorable effect of preventing overflow metabolism, catabolite repression, oxygen limitation or inhibition caused by elevated substrate or osmotic concentrations. Due to these favorable effects, fed-batch mode is predominantly used in industrial production processes. In contrast, screening processes are usually performed in microtiter plates operated in batch mode. This leads to a different physiological state of the production organism in early screening and can misguide the selection of potential production strains. To close the gap between screening and production conditions, new techniques to enable fed-batch mode in microtiter plates have been described. One of these systems is the ready-to-use and disposable polymer-based controlled-release fed-batch microtiter plate (fed-batch MTP). In this work, the fed-batch MTP was applied to establish a glucose-limited fed-batch screening procedure for industrially relevant protease producing Bacillus licheniformis strains. Results To achieve equal initial growth conditions for different clones with the fed-batch MTP, a two-step batch preculture procedure was developed. Based on this preculture procedure, the standard deviation of the protease activity of glucose-limited fed-batch main culture cultivations in the fed-batch MTP was ± 10%. The determination of the number of replicates revealed that a minimum of 6 parallel cultivations were necessary to identify clones with a statistically significant increased or decreased protease activity. The developed glucose-limited fed-batch screening procedure was applied to 13 industrially-relevant clones from two B. licheniformis strain lineages. It was found that 12 out of 13 clones (92%) were classified similarly as in a lab-scale fed-batch fermenter process operated under glucose-limited conditions. When the microtiter plate screening process was performed in batch mode, only 5 out of 13 clones (38%) were classified similarly as in the lab-scale fed-batch fermenter process. Conclusion The glucose-limited fed-batch screening process outperformed the usual batch screening process in terms of the predictability of the clone performance under glucose-limited fed-batch fermenter conditions. These results highlight that the implementation of glucose-limited fed-batch conditions already in microtiter plate scale is crucial to increase the precision of identifying improved protease producing B. licheniformis strains. Hence, the fed-batch MTP represents an efficient high-throughput screening tool that aims at closing the gap between screening and production conditions.

scholarly journals FeedER: a feedback-regulated enzyme-based slow-release system for fed-batch cultivation in microtiter plates

2019 ◽  
Vol 42 (11) ◽  
pp. 1843-1852 ◽  
Author(s):  
Roman Jansen ◽  
Niklas Tenhaef ◽  
Matthias Moch ◽  
Wolfgang Wiechert ◽  
Stephan Noack ◽  
...  
Keyword(s):  
Slow Release ◽  
Batch Cultivation ◽  
Fed Batch ◽  
Release System ◽  
Microtiter Plates ◽  
Fed Batch Cultivation ◽  
Slow Release System

High cell density fed-batch cultivation of Escherichia coli using exponential feeding combined with pH-stat

2004 ◽  
Vol 26 (3) ◽  
pp. 147-150 ◽  
Author(s):  
Beom Soo Kim ◽  
Seung Chul Lee ◽  
Sang Yup Lee ◽  
Yong Keun Chang ◽  
Ho Nam Chang
Keyword(s):  
Escherichia Coli ◽  
Cell Density ◽  
High Cell Density ◽  
Batch Cultivation ◽  
High Cell ◽  
Fed Batch ◽  
Exponential Feeding ◽  
Ph Stat ◽  
Fed Batch Cultivation

scholarly journals Effects of Caprolactam Wastewater on Algal Growth and Nutrients Removal by Arthrospira platensis

2021 ◽  
Vol 12 (1) ◽  
pp. 227
Author(s):  
Youzhi Yu ◽  
Xu Li ◽  
Zhongjie Wang ◽  
Junfeng Rong ◽  
Kaixuan Wang ◽  
...  
Keyword(s):  
Negative Impact ◽  
Algal Growth ◽  
Value Added ◽  
Biomass Productivity ◽  
Arthrospira Platensis ◽  
Batch Cultivation ◽  
Culture Conditions ◽  
Fed Batch ◽  
Batch Mode ◽  
P Removal

Caprolactam wastewater (WCP), which is generated during the production of caprolactam, contains high contents of NO3− and inorganic P and is considered to be difficult to treat. In this study, Arthrospira platensis was used to remove N and P from WCP. Culture conditions and wastewater addition were optimized to relieve the inhibition effects of WCP. The results show that A. platensis growth and photosynthetic activity were inhibited depending on WCP concentrations. The inhibition rates were enhanced as the culture time increased under batch mode. However, the fed-batch mode significantly minimized the negative impact on A. platensis, which is beneficial for removing N and P from WCP by Arthrospira. After 10 d of cultivation of A. platensis in a 25 L circular photobioreactor in fed-batch addition of WCP (1.25% mixed WCP (v/v) each day), the average biomass productivity reached 17.48 g/(m2·d), the maximum protein content was 69.93%, and the N and P removal ratios were 100%. The accumulation effect of WCP inhibition on algal growth was not observed under this culture condition. Fed-batch cultivation of A. platensis is a promising way for bioremediation of WCP with high N and P removal efficiencies and high value-added biomass production.

scholarly journals Optimization of Synthetic Media Composition for Kluyveromyces marxianus Fed-Batch Cultivation

Fermentation ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 62
Author(s):  
Konstantins Dubencovs ◽  
Janis Liepins ◽  
Arturs Suleiko ◽  
Anastasija Suleiko ◽  
Reinis Vangravs ◽  
...  
Keyword(s):  
Kluyveromyces Marxianus ◽  
Reaction Medium ◽  
Value Added ◽  
Batch Cultivation ◽  
Batch Processes ◽  
Biomass Growth ◽  
High Cell ◽  
Media Composition ◽  
Fed Batch ◽  
Fed Batch Cultivation

The Kluyveromyces marxianus yeast recently has gained considerable attention due to its applicability in high-value-added product manufacturing. In order to intensify the biosynthesis rate of a target product, reaching high biomass concentrations in the reaction medium is mandatory. Fed-batch processes are an attractive and efficient way how to achieve high cell densities. However, depending on the physiology of the particular microbial strain, an optimal media composition should be used to avoid by-product synthesis and, subsequently, a decrease in overall process effi-ciency. Thus, the aim of the present study was to optimise the synthetic growth medium and feeding solution compositions (in terms of carbon, nitrogen, phosphorous, magnesium, and calcium concentrations) for high cell density K. marxianus fed‑batch cultivations. Additionally, the biomass yields from the vitamin mixture and other macro/microelements were identified. A model predictive control algorithm was successfully applied for a fed-batch cultivation control. Biomass growth and substrate consumption kinetics were compared with the mathematical model predictions. Finally, 2‑phenylethanol biosynthesis was induced and its productivity was estimated. The determined optimal macronutrient ratio for K. marxianus biomass growth was identified as C:N:P = 1:0.07:0.011. The maximal attained yeast biomass concentration was close to 70 g·L-1 and the 2-PE biosynthesis rate was 0.372 g·L−1·h−1, with a yield of 74% from 2-phenylalanine.

scholarly journals The Influence of Video Format on Engagement and Performance in Online Learning

2021 ◽  
Vol 11 (2) ◽  
pp. 128
Author(s):  
Sergej Lackmann ◽  
Pierre-Majorique Léger ◽  
Patrick Charland ◽  
Caroline Aubé ◽  
Jean Talbot
Keyword(s):  
Student Performance ◽  
Cognitive Engagement ◽  
Emotional Engagement ◽  
Emotional States ◽  
Lecture Capture ◽  
Improved Performance ◽  
And Performance ◽  
Subject Experiment ◽  
The Impact ◽  
Video Format

Millions of students follow online classes which are delivered in video format. Several studies examine the impact of these video formats on engagement and learning using explicit measures and outline the need to also investigate the implicit cognitive and emotional states of online learners. Our study compared two video formats in terms of engagement (over time) and learning in a between-subject experiment. Engagement was operationalized using explicit and implicit neurophysiological measures. Twenty-six (26) subjects participated in the study and were randomly assigned to one of two conditions based on the video shown: infographic video or lecture capture. The infographic video showed animated graphics, images, and text. The lecture capture showed a professor, providing a lecture, filmed in a classroom setting. Results suggest that lecture capture triggers greater emotional engagement over a shorter period, whereas the infographic video maintains higher emotional and cognitive engagement over longer periods of time. Regarding student learning, the infographic video contributes to significantly improved performance in matters of difficult questions. Additionally, our results suggest a significant relationship between engagement and student performance. In general, the higher the engagement, the better the student performance, although, in the case of cognitive engagement, the link is quadratic (inverted U shaped).

scholarly journals Establishing a Fed‐Batch Process for Protease Expression with Bacillus licheniformis in Polymer‐Based Controlled‐Release Microtiter Plates

2019 ◽  
Vol 15 (2) ◽  
pp. 1900088 ◽  
Author(s):  
Tobias Habicher ◽  
Edward K. A. Rauls ◽  
Franziska Egidi ◽  
Timm Keil ◽  
Tobias Klein ◽  
...  
Keyword(s):  
Controlled Release ◽  
Bacillus Licheniformis ◽  
Batch Process ◽  
Fed Batch ◽  
Microtiter Plates ◽  
Protease Expression
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