Metabolic network analysis for human therapeutic protein productions: Effects of the P/O ratio

2000-10-08
The metabolic fluxes through the central carbon pathways in the bioprocesses for human leukocyte interferon (IFN-alpha(1)) and erythropoietin (EPO) overproductions by recombinant Bacillus sp, carrying the related human genes were determined separately, on two alternative carbon sources, i.e. glucose and citrate, which have different reduction degrees. In addition, the influence of the P/O ratio on the cell growth, IFN-alpha(1) and EPO productions were investigated. Thus, the potential influence of increased energy coupling in oxidative phosphorylation is also presented. In parallel to the increase in P/O ratio, with each substrate tested, cell growth and total ATP generation rates increased significantly. The interactions between specific cell growth and protein synthesis rates in the transition periods were analysed for the production of IFN-alpha(1) and EPO. The influence of the P/O ratio on metabolic flux distributions was significant at high specific growth rates; further, with the decrease in the growth rate in the transition period, the IFN-alpha(1) and EPO synthesis fluxes increased. During the product synthesis period (mu = 0 h(-1)) for both substrate, the P/O ratio influences neither the EPO synthesis nor the IFN-alpha(1) synthesis significantly. The potential strategies for improving IFN-alpha(1) and EPO productions are discussed.

Suggestions

Metabolic flux analysis for serine alkaline protease fermentation by Bacillus licheniformis in a defined medium: Effects of the oxygen transfer rate
Çalık, Pınar; Ozdamar, TH (1999-07-01)
The metabolic fluxes through the central carbon pathways in the bioprocess for serine alkaline protease (SAP) production by Bacillus licheniformis were calculated by the metabolic flux-based stoichiometric model based on the proposed metabolic network that contains 102 metabolites and 133 reaction fluxes using the time profiles of citrate, dry cell, organic acids, amino acids, and SAP as the constraints. The model was solved by minimizing the SAP accumulation rate in the cell, The effects of the oxygen-tran...
Metabolic engineering with a novel promoter in Pichia pastoris for recombinant human growth hormone production: effects of oxygen transfer conditions
Kalender, Özge; Çalık, Pınar; Özdamar, Tunçer; Department of Chemical Engineering (2018)
The objectives of this thesis are investigation of, i) the effects of oxygen transfer conditions on recombinant protein production in Pichia pastoris strains designed with novel naturally occuring pyruvate kinase (PYK) promoter (PPYK) which is a potential promoter for recombinant protein production under low to moderate oxygen transfer conditions, and ii) influences of engineering with single- and multi- copy genes, in fed-batch fermentation processes. Production of recombinant human growth hormone (rhGH) b...
Expression System for Recombinant Human Growth Hormone Production from Bacillus subtilis
ÖZDAMAR, HASAN TUNÇER; Sentuerk, Birguel; Yilmaz, Oezge Deniz; Calik, Guezide; Celik, Eda; Çalık, Pınar (2009-01-01)
We demonstrate for the first time, an expression system mimicking serine alkaline protease synthesis and secretion, producing native form of human growth hormone (hGH) from Bacillus subtilis. A hybrid-gene of two DNA fragments, i.e., signal (pre-) DNA sequence of B. licheniformis serine alkaline protease gene (subC) and cDNA encoding hGH, were cloned into pMK4 and expressed under deg-promoter in B. subtilis. Recombinant-hGH (rhGH) produced by B. subtilis carrying pMK4::pre(subC)::hGH was secreted. N-termina...
Metabolic Flux Analysis for Recombinant Protein Production by Pichia pastoris Using Dual Carbon Sources: Effects of Methanol Feeding Rate
Celik, Eda; Çalık, Pınar; Oliver, Stephen G. (Wiley, 2010-02-01)
The intracellular metabolic fluxes through the central carbon pathways in the bioprocess for recombinant human erythropoietin (rHuEPO) production by Pichia pastoris (Mut(+)) were calculated. to investigate the metabolic effects of dual carbon sources (methanol/sorbitol) and the methanol feed rate, and to obtain a deeper understanding the regulatory circuitry of P. pastoris, using the established stoichiometry-based model containing 102 metabolites and 141 reaction fluxes. Four fed-batch operations with (MS-...
Metabolic flux analyses for serine alkaline protease production
Çalık, Pınar; Ozdamar, TH (2000-12-01)
The intracellular metabolic fluxes through the central carbon pathways in Bacillus licheniformis in serine alkaline protease (SAP) production were calculated to predict the potential strategies for increasing the performance of the bacilli, by using two optimization approaches, i.e. the theoretical data-based (TDA) and the theoretical data-based capacity (TDC) analyses based on respectively minimum in-vivo SAP accumulation rate and maximum SAP synthesis rate assumptions, at low-, medium, and high-oxygen tra...
Citation Formats
P. Çalık, “Metabolic network analysis for human therapeutic protein productions: Effects of the P/O ratio,” 2000, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/55510.