Macromolecular and elemental composition analysis and extracellular metabolite balances of Pichia pastoris growing at different oxygen levels
Open Access
- 9 December 2009
- journal article
- Published by Springer Science and Business Media LLC in Microbial Cell Factories
- Vol. 8 (1), 65
- https://doi.org/10.1186/1475-2859-8-65
Abstract
Background: Analysis of the cell operation at the metabolic level requires collecting data of different types and to determine their confidence level. In addition, the acquired information has to be combined in order to obtain a consistent operational view. In the case ofPichia pastoris, information of its biomass composition at macromolecular and elemental level is scarce particularly when different environmental conditions, such as oxygen availability or, genetic backgrounds (e.g. recombinant protein productionvs. non production conditions) are compared.Results: P. pastoriscells growing in carbon-limited chemostat cultures under different oxygenation conditions (% O2in the bioreactor inlet gas: 21%, 11% and 8%, corresponding to normoxic, oxygen-limiting and hypoxic conditions, respectively), as well as under recombinant protein (antibody fragment, Fab) producing and non-producing conditions, were analyzed from different points of view. On the one hand, the macromolecular and elemental composition of the biomass was measured using different techniques at the different experimental conditions and proper reconciliation techniques were applied for gross error detection of the measured substrates and products conversion rates. On the other hand, fermentation data was analyzed applying elemental mass balances. This allowed detecting a previously missed by-product secreted under hypoxic conditions, identified as arabinitol (aka. arabitol). After identification of this C5 sugar alcohol as a fermentation by-product, the mass balances of the fermentation experiments were validated.Conclusions: After application of a range of analytical and statistical techniques, a consistent view of growth parameters and compositional data ofP. pastoriscells growing under different oxygenation conditions was obtained. The obtained data provides a first view of the effects of oxygen limitation on the physiology of this microorganism, while recombinant Fab production seems to have little or no impact at this level of analysis. Furthermore, the results will be highly useful in other complementary quantitative studies ofP. pastorisphysiology, such as metabolic flux analysis.Keywords
This publication has 35 references indexed in Scilit:
- Yeast systems biotechnology for the production of heterologous proteinsFEMS Yeast Research, 2009
- Genome, secretome and glucose transport highlight unique features of the protein production host Pichia pastorisMicrobial Cell Factories, 2009
- Reconstruction of biochemical networks in microorganismsNature Reviews Microbiology, 2008
- The genome-scale metabolic model iIN800 of Saccharomyces cerevisiae and its validation: a scaffold to query lipid metabolismBMC Systems Biology, 2008
- The growing scope of applications of genome-scale metabolic reconstructions using Escherichia coliNature Biotechnology, 2008
- Integrating high-throughput and computational data elucidates bacterial networksNature, 2004
- Multiple Positive and Negative Elements Involved in the Regulation of Expression of GSY1 in Saccharomyces cerevisiaeOnline Journal of Public Health Informatics, 2003
- Life with 6000 GenesScience, 1996
- Sugar‐ and salt‐tolerant yeastsJournal of Applied Bacteriology, 1993
- A 13C comparative nuclear magnetic resonance study of organic solute production and excretion by the yeasts Hansenula anomala and Saccharomyces cerevisiae in saline mediaCanadian Journal of Microbiology, 1988