Dynamic flux balance analysis for pharmaceutical protein production by Pichia pastoris: Human growth hormone

Çalık, Pınar
Taspinar, Hatice
Soyaslan, Elif S.
Inankur, Bahar
The influence of methanol feeding rate on intracellular reaction network of recombinant human growth hormone (rhGH) producing Pichia pastoris was investigated at three different specific growth rates, namely, 0.02 (MS-0.02), 0.03 (MS-0.03), and 0.04h(-1) (MS-0.04) where Period-I (33 <= t < 42 h) includes the early exponential growth phase; Period-II (42 <= t < 48 h) is the exponential growth phase where the specific cell growth rate decreases; Period-III (48 <= t <= 51 h) is the exponential growth phase where rhGH concentration was the highest; and Period-IV (t > 51 h) is the diminution phase for rhGH and cell synthesis. In Period-I, almost all of the formaldehyde entered the assimilatory pathway, at MS-0.02 and MS-0.03, whereas, at MS-0.04 high methanol feeding rate resulted in an adaptation problem. In Period-III, only at MS-0.02 co-carbon source sorbitol uptake-flux was active showing that sorbitol uptake does not affected from the predetermined feeding rate of methanol at mu(0) > 0.02 h(-1). The biomass synthesis flux value was the highest in Period-I, -II and -III, respectively at MS-0.03 & MS-0.04, MS-0.04 and MS-0.02; whereas, rhGH flux was the highest in Period-I, -II, and -III, respectively at MS-0.03, MS-0.02 and MS-0.03. Based on the fluxes, Period-I should start with MS-0.03 methanol feeding rate and starting from the middle of Period-II methanol feeding rate should be shifted to MS-0.02. (c) 2010 Elsevier Inc. All rights reserved.


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Experimental data were modeled based on the literature for the production of nine different amino acids by ten different mutant over-producer microorganisms. Mathematical modeling helped to better understand common aspects of these fermentations, which were not stressed previously by plotting the data only. A Luedeking-Piret type of a model was found to be valid for representing all the amino acid production data. This result indicated the similarity among the amino acid production patterns of all the mutan...
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Kocabıyık, Semra; Zwickl, Peter; Ozdogan, Seda (Elsevier BV, 2010-10-01)
In this study we describe, the construction of a co-expression vector allowing simultaneous production of Thermoplasma volcanium 20S proteasome alpha- and beta-subunits in Escherichia coli. This heterologous expression system provided high level production of fully active 205 proteasome that can be purified easily by using a conventional two-step chromatographic technique. The recombinant proteasome was purified to homogeneity 12-fold with a specific activity of 26.5 U/mg. Sodium dodecyl sulfate-polyacrylam...
Determination and metabolic engineering of rate limiting reactions in aromatic amino acid pathway in Bacillus subtilis for L-phenylaianine production
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Rate limiting reactions in the aromatic-group amino acid pathway (AAAP) in Bacillus subtilis for l-phenylalanine (Phe) production were determined as reported elsewhere (Özçelik-Şenver et al., 2004). The biochemical reactions in the AAAP start with the reaction using phosphoenolpyruvate (PEP) and erythrose 4-phosphate (E4P) synthesised in the glycolysis pathway and the PPP, respectively, leading to the formation of Phe via chorismate by branching at prephenate. The branch-point metabolites E4P supplied in vi...
AKDOGAN, H; OZILGEN, M (Elsevier BV, 1992-02-01)
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Citation Formats
P. Çalık, H. Taspinar, E. S. Soyaslan, and B. Inankur, “Dynamic flux balance analysis for pharmaceutical protein production by Pichia pastoris: Human growth hormone,” ENZYME AND MICROBIAL TECHNOLOGY, pp. 209–216, 2011, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/34439.