Fed-batch process for the psychrotolerant marine bacterium Pseudoalteromonas haloplanktis

Microbial Cell Factories

Research

Peter Neubauer¹  Michael Lalk²  Manuel Liebeke³  Boris Wilmes⁴  Thomas Schweder⁵  Angelika Hartung⁶ 

[1]Bioprocess Engineering Laboratory, University of Oulu, P.O.Box 4300, FI-9001, Oulu, Finland

[2]Laboratory of Bioprocess Engineering, Department of Biotechnology, Technical University Berlin, Ackerstr. 71-76, D-13355, Berlin, Germany

[3]Competence Center - Functional Genomics, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-17487, Greifswald, Germany

[4]Competence Center - Functional Genomics, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-17487, Greifswald, Germany

[5]Biomolecular Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, SW7 2AZ, London, UK

[6]Institute of Marine Biotechnology, W.-Rathenau-Str. 49, D-17489, Greifswald, Germany

[7]Pharmaceutical Biotechnology, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-1748, Greifswald, Germany

[8]Bioprocess Engineering Laboratory, University of Oulu, P.O.Box 4300, FI-9001, Oulu, Finland

[9]Institute of Marine Biotechnology, W.-Rathenau-Str. 49, D-17489, Greifswald, Germany

[10]Pharmaceutical Biotechnology, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-1748, Greifswald, Germany

[11]Competence Center - Functional Genomics, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-17487, Greifswald, Germany

[12]Pharmaceutical Biotechnology, Institute of Pharmacy, Ernst-Moritz-Arndt-University, F.-L.-Jahn-Str. 17, D-1748, Greifswald, Germany

[13]Bioprocess Engineering Laboratory, University of Oulu, P.O.Box 4300, FI-9001, Oulu, Finland

[14]Department of Internal Medicine IV, University of Tübingen, Otfried-Müller Str.10, D-72076, Tübingen, Germany

关键词: Specific Growth Rate;    Casamino Acid;    Dissolve Oxygen Tension;    Final Optical Density;    Final Cell Density;   

DOI  :  10.1186/1475-2859-9-72

 received in 2010-07-13, accepted in 2010-09-21,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundPseudoalteromonas haloplanktis is a cold-adapted γ-proteobacterium isolated from Antarctic sea ice. It is characterized by remarkably high growth rates at low temperatures. P. haloplanktis is one of the model organisms of cold-adapted bacteria and has been suggested as an alternative host for the soluble overproduction of heterologous proteins which tend to form inclusion bodies in established expression hosts. Despite the progress in establishing P. haloplanktis as an alternative expression host the cell densities obtained with this organism, which is unable to use glucose as a carbon source, are still low. Here we present the first fed-batch cultivation strategy for this auspicious alternative expression host.ResultsThe key for the fed-batch cultivation of P. haloplanktis was the replacement of peptone by casamino acids, which have a much higher solubility and allow a better growth control. In contrast to the peptone medium, on which P. haloplanktis showed different growth phases, on a casamino acids-containing, phosphate-buffered medium P. haloplanktis grew exponentially with a constant growth rate until the stationary phase. A fed-batch process was established by feeding of casamino acids with a constant rate resulting in a cell dry weight of about 11 g l-1 (OD540 = 28) which is a twofold increase of the highest densities which have been obtained with P. haloplanktis so far and an eightfold increase of the density obtained in standard shake flask cultures.The cell density was limited in the fed-batch cultivation by the relatively low solubility of casamino acids (about 100 g l-1), which was proven by pulse addition of casamino acid powder which increased the cell density to about 20 g l-1 (OD540 = 55).ConclusionThe growth of P. haloplanktis to higher cell densities on complex medium is possible. A first fed-batch fermentation strategy could be established which is feasible to be used in lab-scale or for industrial purposes. The substrate concentration of the feeding solution was found to influence the maximal biomass yield considerably. The bottleneck for growing P. haloplanktis to high cell densities still remains the availability of a highly concentrated substrate and the reduction of the substrate complexity. However, our results indicate glutamic acid as a major carbon source, which provides a good basis for further improvement of the fed-batch process.

【 授权许可】

Unknown   
© Wilmes et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.