Glucose-based feeding strategy development in recombinant human growth hormone production by ichia pastoris for semi-batch bioreactor operation

Download
2014
Keskin, Abdullah
The aim of this study was to develop an effective feeding strategy to enhance recombinant human growth hormone (rhGH) production by Pichia pastoris Mut+ strain harboring pGAPZαA::hGH which is integrated to glyceraldehyde-3-phosphate dehydrogenase gene (GAP) locus of P. pastoris. In this context, eight semi-batch bioreactor experiments were conducted at pilot-scale; their batch phase was same in which glycerol was used as the sole carbon source. For semi-batch operation phase, eight feeding strategies were designed using exponential substrate feeding, constant substrate feeding, specific substrate consumption rate based substrate feeding, and combination of these feeding modes. The feeding strategies were designed by using three different pre-determined specific growth rates, μ0=0.10, 0.15, and 0.175 h-1, two constant volumetric flow rates of glucose, Q(t≥15 h) =12 ml h-1 or Q(t≥11 h) =24 ml h-1, and one constant specific glucose consumption rate, qS=0.05 g g-1 h-1. Further, to investigate the effects of carbon sources, glucose and pre-treated molasses were used. The best feeding strategy was the one conducted based on exponential glucose feeding with the pre-determined specific growth rate of μ0= 0.15 h-1 wherein the highest rhGH was attained as CrhGH = 508 mg L-1 at t=19 h and the cell concentration was CX =65.4 g L-1. The overall product and cell yield on total substrate were obtained as Y’P/S = 1.9 mg g-1 and Y’X/S=0.22 g g-1, respectively.

Suggestions

Feeding strategy development for human growth hormone production by Pichia pastoris
Bozkurt, Bahar; Çalık, Pınar; Özdamar, Tunçer H.; Department of Biotechnology (2012)
In this study, recombinant human growth hormone (rhGH) production by Pichia pastoris-Mut+ strain was improved by designing feeding strategies which were applied in the production phase of the bioreactor operations. During the bio-reactor experiments the cell growth, sorbitol and methanol consumptions, recom-binant hGH production, alcohol oxidase (AOX) activity, the by-products protease and organic acid concentrations were followed and analyzed. In this context, in the first part of the study, three bioreact...
Defined and complex medium based feeding strategy development for recombinant human growth hormone production by P. pastoris under GAP promoter
Hoxha, Bebeta; Çalık, Pınar; Özdamar, Tunçer H.; Department of Chemical Engineering (2016)
The objective of this study is to investigate different feeding strategies leading to higher recombinant human growth hormone (rhGH) production by Pichia pastoris, driven under constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene. rhGH production took place in a pilot bioreactor where glucose and molasses were examined as carbon sources. For batch phase, which is the first production phase of the reactor, all experiments share the same characteristics where glycerol was utilized as the...
Feeding strategy design for recombinant human growth hormone production by Bacillus subtilis
Sahin, Burcu; Ozturk, Sibel; Çalık, Pınar; Ozdamar, Tuncer H. (2015-10-01)
Defined and semi-defined medium-based feeding strategies were developed to enhance recombinant human growth hormone (rhGH) production by Bacillus subtilis BGSC-1A178 (scoC (-)) strain carrying pMK4::pre(subC)::hGH. Defined medium-based feeding strategies were designed by exponential feeding of glucose and (NH4)(2)HPO4 at two pre-determined specific growth rates, A mu (0) = 0.10 and 0.17 h(-1). Semi-defined medium-based feeding strategies were designed by exponential feeding of substrate solution consisting ...
Metabological engineering of Pichia Pastoris for extracellular thermostable glucose isomerase production
Ata, Özge; Çalık, Pınar; Özdamar, Tunçer H.; Department of Biotechnology (2012)
The aim of this study is to develop a metabolically engineered P. pastoris strain for production of an active extracellular thermostable glucose isomerase (GI) enzyme by using genetic engineering techniques. For this purpose, research program was performed in two sub-programs. In the first sub-program, xylA gene from Thermus thermophilus was amplified and inserted into pPICZα-A expression vector. Thereafter, this pPICZα-A::xylA vector was cloned into AOX1 locus in P. pastoris genome and expressed under alco...
Effects of ph on human growth hormone production by pichia pastoris considering the expression levels of regulatory genes
Bayraktar, Eda; Çalık, Pınar; Department of Chemical Engineering (2009)
In this study, the aim was to investigate the effects of pH on therapeutically important protein, recombinant human growth hormone (rhGH), production by Pichia pastoris considering the expression levels of regulatory genes. In this frame, firstly the host microorganism was selected between two different methanol utilization phenotypes of P. pastoris, Mut+ and MutS on media containing glycerol/methanol or sorbitol/methanol. The highest rhGH production, 120 g L-1, and hGH gene expression, 9.84x109 copies mg-1...
Citation Formats
A. Keskin, “Glucose-based feeding strategy development in recombinant human growth hormone production by ichia pastoris for semi-batch bioreactor operation,” M.S. - Master of Science, Middle East Technical University, 2014.