Investigation of poly(γ-glutamic acid) production via online determination of viscosity and oxygen transfer rate in shake flasks

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Background

Poly(γ-glutamic acid) (γ-PGA) is a biopolymer with many useful properties making it applicable for instance in food and skin care industries, in wastewater treatment, in biodegradable plastics or in the pharmaceutical industry. γ-PGA is usually produced microbially by different Bacillus spp. The produced γ-PGA increases the viscosity of the fermentation broth. In case of shake flask fermentations, this results in an increase of the volumetric power input. The power input in shake flasks can be determined by measuring the torque of an orbitally rotating lab shaker. The online measurement of the volumetric power input enables to continuously monitor the formation or degradation of viscous products like γ-PGA. Combined with the online measurement of the oxygen transfer rate (OTR), the respiration activity of the organisms can be observed at the same time.

Results

Two different Bacillus licheniformis strains and three medium compositions were investigated using online volumetric power input and OTR measurements as well as thorough offline analysis. The online volumetric power input measurement clearly depicted changes in γ-PGA formation due to different medium compositions as well as differences in the production behavior of the two investigated strains. A higher citric acid concentration and the addition of trace elements to the standard medium showed a positive influence on γ-PGA production. The online power input signal was used to derive an online viscosity signal which was validated with offline determined viscosity values. The online measurement of the OTR proved to be a valuable tool to follow the respiration activity of the cultivated strains and to determine its reproducibility under different cultivation conditions.

Conclusions

The combination of the volumetric power input and the OTR allows for an easy and reliable investigation of new strains, cultivation conditions and medium compositions for their potential in γ-PGA production. The power input signal and the derived online viscosity directly reflect changes in γ-PGA molecular weight and concentration, respectively, due to different cultivation conditions or production strains.

Electronic supplementary material

The online version of this article (doi:10.1186/s13036-017-0065-4) contains supplementary material, which is available to authorized users.

Related collections

Most cited references 45

Record: found
Abstract: not found
Article: not found

Catabolic repression of bacterial sporulation.

J-F Aubert, Larry Millet, P Schaeffer (1965)

0 comments Cited 139 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Biotechnological production of 2,3-butanediol--current state and prospects.

E Celińska, W Grajek (2009)

Biotechnological production of 2,3-butanediol (hereafter referred to as 2,3-BD) from wastes and excessive biomass is a promising and attractive alternative for traditional chemical synthesis. In the face of scarcity of fossil fuel supplies the bio-based process is receiving a significant interest, since 2,3-BD may have multiple practical applications (e.g. production of synthetic rubber, plasticizers, fumigants, as an antifreeze agent, fuel additive, octane booster, and many others). Although the 2,3-BD pathway is well known, microorganisms able to ferment biomass to 2,3-BD have been isolated and described, and attempts of pilot scale production of this compound were made, still much has to be done in order to achieve desired profitability. This review summarizes hitherto gained knowledge and experience in biotechnological production of 2,3-BD, sources of biomass used, employed microorganisms both wild type and genetically improved strains, as well as operating conditions applied.

0 comments Cited 125 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: not found
Article: not found

Online respiration activity measurement (OTR, CTR, RQ) in shake flasks

Tibor Anderlei, Werner Zang, Manfred Papaspyrou … (2004)

0 comments Cited 83 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Contributors

Lena Regestein née Meissner:

ORCID: http://orcid.org/0000-0003-1394-2745

lena.regestein@avt.rwth-aachen.de

Julia Arndt: julia.arndt1@rwth-aachen.de

Thomas G. Palmen: thomas.palmen@avt.rwth-aachen.de

Tim Jestel: tim.jestel@avt.rwth-aachen.de

Hitoshi Mitsunaga: hitoshi_mitsunaga@bio.eng.osaka-u.ac.jp

Eiichiro Fukusaki: fukusaki@bio.eng.osaka-u.ac.jp

Jochen Büchs: +49 241 8024633 , jochen.buechs@avt.rwth-aachen.de

Journal

Journal ID (nlm-ta): J Biol Eng

Journal ID (iso-abbrev): J Biol Eng

Title: Journal of Biological Engineering

Publisher: BioMed Central (London )

ISSN (Electronic): 1754-1611

Publication date (Electronic): 12 July 2017

Publication date PMC-release: 12 July 2017

Publication date Collection: 2017

Volume: 11

Electronic Location Identifier: 23

Affiliations

[1 ]ISNI 0000 0001 0728 696X, GRID grid.1957.a, AVT - Biochemical Engineering, , RWTH Aachen University, ; Forckenbeckstr. 51, 52074 Aachen, Germany

[2 ]ISNI 0000 0001 0728 696X, GRID grid.1957.a, AVT - Enzyme Process Technology, , RWTH Aachen University, ; Forckenbeckstr. 51, 52074 Aachen, Germany

[3 ]ISNI 0000 0004 0373 3971, GRID grid.136593.b, Department of Biotechnology, Graduate School of Engineering, , Osaka University, ; 2-1 Yamadaoka, Suita, Osaka, 565-0871 Japan

Author information

Lena Regestein née Meissner http://orcid.org/0000-0003-1394-2745

Article

Publisher ID: 65

DOI: 10.1186/s13036-017-0065-4

PMC ID: 5506581

PubMed ID: 28702080

SO-VID: 8e67392c-db53-463a-8a59-1d2aa1b23538

License:

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

History

Date received : 20 March 2017

Date accepted : 29 May 2017

Funding

Funded by: FundRef http://dx.doi.org/10.13039/501100001659, Deutsche Forschungsgemeinschaft;

Award ID: GRK 1628

Award Recipient : Lena Regestein née Meissner

Custom metadata

ScienceOpen disciplines: Biotechnology

Keywords: bacillus licheniformis,online volumetric power input,effective viscosity,shake flask

Data availability:

ScienceOpen disciplines: Biotechnology

Keywords: bacillus licheniformis, online volumetric power input, effective viscosity, shake flask

Investigation of poly(γ-glutamic acid) production via online determination of viscosity and oxygen transfer rate in shake flasks

Read this article at

Abstract

Background

Results

Conclusions

Electronic supplementary material

Related collections

Genome Engineering using CRISPR

Most cited references 45

Catabolic repression of bacterial sporulation.

Biotechnological production of 2,3-butanediol--current state and prospects.

Online respiration activity measurement (OTR, CTR, RQ) in shake flasks

Author and article information

Contributors

Journal

Affiliations

Author information

Article

History

Funding

Categories

Custom metadata

Comments

Comment on this article

Similar content 17

Cited by 3

Most referenced authors 348