On‐Line Exhaust Gas Analysis of Volatiles in Fermentation Using Mass Spectrometry

Oeggerli, A.; Heinzle, Elmar

doi:10.1021/bp00027a008

Cited by 16 publications

(6 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…6 On the contrary, when the CO 2 stripping rate is lower that its production rate (e.g., using low agitation and/or aeration conditions), the dissolved CO 2 concentration rises above the saturation value (CO 2sat ). 7 In this case, wastewaters with high concentrations of Ca 2+ and/or Mg + lead to the formation of highly insoluble carbonates. 8 Although the carbon dioxide mass transfer coefficient is an important feature of reactor design, few direct measurements were reported.…”

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Stripping In Bubbled Columns

Contreras

2007

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

The carbonate buffer system plays a fundamental role in the biological treatments of wastewaters. In this work, the CO 2 volumetric mass transfer coefficient (k L a c ) in a bubbled column was determined using the conventional titration method for different column volumes and air flow rates. In addition, a simple method to determine k L a c based on the interpretation of the changes in the pH level due to the CO 2 stripping was developed. Results show that the apparent CO 2 volumetric mass transfer coefficient (k L a c-app ) was strongly affected by the pH level; however, the actual CO 2 volumetric mass transfer coefficient, k L a c ) k L a c-app /R 0 , was constant within the tested pH conditions. In addition, k L a c increased with higher air flow rates and lower column volumes; the obtained k L a c values ranged between 20.0 and 71.9 h -1 . For all the tested conditions, k L a c values obtained using the noncontrolled pH method were similar to the values measured using the titrimetric method. The proposed mathematical model represented adequately the changes on the pH level and total inorganic carbon species concentration as a function of time. The model was extended to take into account the effect of phosphates. Simulation results showed that, although phosphates buffered the changes of pH, the losses of total inorganic carbon were faster than in the case of a nonbuffered solution; thus, the rise in the pH level prevented the stripping of CO 2 .

show abstract

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Stripping In Bubbled Columns

Contreras

2007

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…When performed in a particle-free sample, the use of spectroscopic methods will suddenly become a lot easier at the industrial scale. Another method of performing advanced particle-free on-line measurements is by performing mass spectrometry on the offgas, thus extending the range of measured components far beyond traditional O 2 and CO 2 off-gas measurements . Online MS is increasingly applied on the off-gas in fermentation laboratories and will probably also become more popular in industry in the forthcoming years.…”

Section: Applications Of Pat Based Process Monitoring and Controlmentioning

confidence: 99%

Assessment of Recent Process Analytical Technology (PAT) Trends: A Multiauthor Review

Simon

Pataki

Marosi

et al. 2015

Org. Process Res. Dev.

359

238

View full text Add to dashboard Cite

This multiauthor review article aims to bring readers up to date with some of the current trends in the field of process analytical technology (PAT) by summarizing each aspect of the subject (sensor development, PAT based process monitoring and control methods) and presenting applications both in industrial laboratories and in manufacture e.g. at GSK, AstraZeneca and Roche. Furthermore, the paper discusses the PAT paradigm from the regulatory science perspective. Given the multidisciplinary nature of PAT, such an endeavour would be almost impossible for a single author, so the concept of a multiauthor review was born. Each section of the multiauthor review has been written by a single expert or group of experts with the aim to report on its own research results. This paper also serves as a comprehensive source of information on PAT topics for the novice reader.

show abstract

“…Another method is direct headspace sampling. This simple method has been used to monitor concentrations of several compounds in fermentation processes, as in Bacillus subtilis cultures (Heinzle, 1987; Oeggerli and Heinzle, 1994).…”

Section: Introductionmentioning

confidence: 99%

Implementation of proton transfer reaction‐mass spectrometry (PTR‐MS) for advanced bioprocess monitoring

Luchner

Gutmann

Bayer

et al. 2012

Biotech & Bioengineering

View full text Add to dashboard Cite

We report on the implementation of proton transfer reaction-mass spectrometry (PTR-MS) technology for on-line monitoring of volatile organic compounds (VOCs) in the off-gas of bioreactors. The main part of the work was focused on the development of an interface between the bioreactor and an analyzer suitable for continuous sampling of VOCs emanating from the bioprocess. The permanently heated sampling line with an inert surface avoids condensation and interaction of volatiles during transfer to the PTR-MS. The interface is equipped with a sterile sinter filter unit directly connected to the bioreactor headspace, a condensate trap, and a series of valves allowing for dilution of the headspace gas, in-process calibration, and multiport operation. To assess the aptitude of the entire system, a case study was conducted comprising three identical cultivations with a recombinant E. coli strain, and the volatiles produced in the course of the experiments were monitored with the PTR-MS. The high reproducibility of the measurements proved that the established sampling interface allows for reproducible transfer of volatiles from the headspace to the PTR-MS analyzer. The set of volatile compounds monitored comprises metabolites of different pathways with diverse functions in cell physiology but also volatiles from the process matrix. The trends of individual compounds showed diverse patterns. The recorded signal levels covered a dynamic range of more than five orders of magnitude. It was possible to assign specific volatile compounds to distinctive events in the bioprocess. The presented results clearly show that PTR-MS was successfully implemented as a powerful bioprocess-monitoring tool and that access to volatiles emitted by the cells opens promising perspectives in terms of advanced process control.

show abstract

On‐Line Exhaust Gas Analysis of Volatiles in Fermentation Using Mass Spectrometry

Cited by 16 publications

References 16 publications

Carbon Dioxide Stripping In Bubbled Columns

Carbon Dioxide Stripping In Bubbled Columns

Assessment of Recent Process Analytical Technology (PAT) Trends: A Multiauthor Review

Implementation of proton transfer reaction‐mass spectrometry (PTR‐MS) for advanced bioprocess monitoring

Contact Info

Product

Resources

About