Mass transfer resistance of sterile plugs in shaking bioreactors

Mrotzek, Christian; Anderlei, Tibor; Henzler, Hans‐Jürgen; Büchs, Jochen

doi:10.1016/s1369-703x(00)00108-x

Cited by 61 publications

(53 citation statements)

References 4 publications

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“…is similar to Eq. 4 for oxygen), and for shake flasks a model describing the mass transfer resistance of the sterile plug (Henzler and Schedel, 1991;Mrotzek et al, 2001).…”

Section: Description Of the Ph Modelmentioning

confidence: 99%

Scale‐up from shake flasks to fermenters in batch and continuous mode with Corynebacterium glutamicum on lactic acid based on oxygen transfer and pH

Seletzky

Noak

Fricke

et al. 2007

Biotech & Bioengineering

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Scale-up from shake flasks to fermenters has been hampered by the lack of knowledge concerning the influence of operating conditions on mass transfer, hydromechanics, and power input. However, in recent years the properties of shake flasks have been described with empirical models. A practical scale-up strategy for everyday use is introduced for the scale-up of aerobic cultures from shake flasks to fermenters in batch and continuous mode. The strategy is based on empirical correlations of the volumetric mass transfer coefficient (k(L) a) and the pH. The accuracy of the empirical k(L) a correlations and the assumptions required to use these correlations for an arbitrary biological medium are discussed. To determine the optimal pH of the culture medium a simple laboratory method based on titration curves of the medium and a mechanistic pH model, which is solely based on the medium composition, is applied. The effectiveness of the scale-up strategy is demonstrated by comparing the behavior of Corynebacterium glutamicum on lactic acid in shake flasks and fermenters in batch and continuous mode. The maximum growth rate (micro(max) = 0.32 h(-1)) and the oxygen substrate coefficient (Y O2 /S= 0.0174 mol/l) of C. glutamicum on lactic acid were equal for shake flask, fermenter, batch, and continuous cultures. The biomass substrate yield was independent of the scale, but was lower in batch cultures (Y(X/S) = 0.36 g/g) than in continuous cultures (Y(X/S) = 0.45 g/g). The experimental data (biomass, respiration, pH) could be described with a simple biological model combined with a mechanistic pH model.

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“…is similar to Eq. 4 for oxygen), and for shake flasks a model describing the mass transfer resistance of the sterile plug (Henzler and Schedel, 1991;Mrotzek et al, 2001).…”

Section: Description Of the Ph Modelmentioning

confidence: 99%

Scale‐up from shake flasks to fermenters in batch and continuous mode with Corynebacterium glutamicum on lactic acid based on oxygen transfer and pH

Seletzky

Noak

Fricke

et al. 2007

Biotech & Bioengineering

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“…By applying methods developed for the evaluation of the mass transfer resistance of the sterile plug in shaking flasks (10,16), the minimum concentration in the headspace of the wells (representing the mass transfer resistance of our lid) was estimated. At a maximum OTR of 38 mmol liter Ϫ1 h Ϫ1 and a filling volume of 500 l, the minimum headspace oxygen concentration was calculated to be 18% (vol/vol).…”

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confidence: 99%

Methods for Intense Aeration, Growth, Storage, and Replication of Bacterial Strains in Microtiter Plates

Duetz

Rüedi

Hermann

et al. 2000

Appl Environ Microbiol

317

259

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Miniaturized growth systems for heterogeneous culture collections are not only attractive in reducing demands for incubation space and medium but also in making the parallel handling of large numbers of strains more practicable. We report here on the optimization of oxygen transfer rates in deep-well microtiter plates and the development of a replication system allowing the simultaneous and reproducible sampling of 96 frozen glycerol stock cultures while the remaining culture volume remains frozen. Oxygen transfer rates were derived from growth curves of Pseudomonas putida and from rates of oxygen disappearance due to the cobalt-catalyzed oxidation of sulfite. Maximum oxygen transfer rates (38 mmol liter ؊1 h ؊1 , corresponding to a mass transfer coefficient of 188 h ؊1 ) were measured during orbital shaking at 300 rpm at a shaking diameter of 5 cm and a culture volume of 0.5 ml. A shaking diameter of 2.5 cm resulted in threefold-lower values. These high oxygen transfer rates allowed P. putida to reach a cell density of approximately 9 g (dry weight) liter ؊1 during growth on a glucose mineral medium at culture volumes of up to 1 ml. The growth-and-replication system was evaluated for a culture collection consisting of aerobic strains, mainly from the genera Pseudomonas, Rhodococcus, and Alcaligenes, using mineral media and rich media. Cross-contamination and excessive evaporation during vigorous aeration were adequately prevented by the use of a sandwich cover of spongy silicone and cotton wool on top of the microtiter plates.The general practice during screening of large microbial strain collections for new enzyme activities or bioactive compounds is that each strain is handled individually. The labor and time involved in separately reviving the stock cultures on agar plates and the subsequent inoculation of tubes or Erlenmeyer flasks are major limiting factors in the progress of such screening projects. This bottleneck might be alleviated if large numbers of microbial strains could be handled in parallel rather than in sequence, preferably in a format that is compatible with current standards in the manipulation of large numbers of liquid samples, e.g., in 96-or 384-well microtiter plates.Until now, the use of microtiter plates for the growth and maintenance of microbial strains has been mainly limited to clonal libraries in Escherichia coli (9,11,20) and yeasts (2, 18). For this purpose, the apparent drawbacks of growth in microtiter plates-low aeration rates and small working volumesare generally less relevant since E. coli and yeasts can grow anaerobically. Furthermore, small amounts of biomass generally suffice as the use of high-copy-number vectors ensures high levels of the desired gene or gene product. The resulting mixed aerobic-anaerobic growth, however, can lead to undesirable variations in biomass levels from well to well, especially since oxygen diffusion rates for an individual well may be affected by its position in the microtiter plate. Such well-to-well variations are especially troublesome in...

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“…These ports are necessary for supplying gas, purging exhaust gas, inoculating the culture, and connecting an electrochemical oxygen sensor located in the headspace of the flasks. The aeration of 10 ml min Ϫ1 per flask is adjusted by a thermal mass flow controller to guarantee similar aeration conditions as in normal shake flasks with a cotton plug (28,29). To determine the OTR, the valves for gas inlet and outlet for each flask were periodically closed (5 min closed and 15 min open).…”

Section: Methodsmentioning

confidence: 99%

Evidence for a Key Role of Cytochrome bo3 Oxidase in Respiratory Energy Metabolism of Gluconobacter oxydans

Richhardt

Luchterhand

Bringer

et al. 2013

Journal of Bacteriology

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The obligatory aerobic acetic acid bacterium Gluconobacter oxydans oxidizes a variety of substrates in the periplasm by membrane-bound dehydrogenases, which transfer the reducing equivalents to ubiquinone. Two quinol oxidases, cytochrome bo 3 and cytochrome bd, then catalyze transfer of the electrons from ubiquinol to molecular oxygen. In this study, mutants lacking either of these terminal oxidases were characterized. Deletion of the cydAB genes for cytochrome bd had no obvious influence on growth, whereas the lack of the cyoBACD genes for cytochrome bo 3 severely reduced the growth rate and the cell yield. Using a respiration activity monitoring system and adjusting different levels of oxygen availability, hints of a low-oxygen affinity of cytochrome bd oxidase were obtained, which were supported by measurements of oxygen consumption in a respirometer. The H ؉ /O ratio of the ⌬cyoBACD mutant with mannitol as the substrate was 0.56 ؎ 0.11 and more than 50% lower than that of the reference strain (1.26 ؎ 0.06) and the ⌬cydAB mutant (1.31 ؎ 0.16), indicating that cytochrome bo 3 oxidase is the main component for proton extrusion via the respiratory chain. Plasmid-based overexpression of cyoBACD led to increased growth rates and growth yields, both in the wild type and the ⌬cyoBACD mutant, suggesting that cytochrome bo 3 might be a rate-limiting factor of the respiratory chain.

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Mass transfer resistance of sterile plugs in shaking bioreactors

Cited by 61 publications

References 4 publications

Scale‐up from shake flasks to fermenters in batch and continuous mode with Corynebacterium glutamicum on lactic acid based on oxygen transfer and pH

Scale‐up from shake flasks to fermenters in batch and continuous mode with Corynebacterium glutamicum on lactic acid based on oxygen transfer and pH

Methods for Intense Aeration, Growth, Storage, and Replication of Bacterial Strains in Microtiter Plates

Evidence for a Key Role of Cytochrome bo3 Oxidase in Respiratory Energy Metabolism of Gluconobacter oxydans

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