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Effect of oxygen transfer conditions on recombinant protein production by Pichia pastoris under glyceraldehyde 3 phosphate dehydrogenase promoter
Date
2016-04-06
Author
Güneş, Hande
Çalık, Pınar
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Glyceraldehyde-3-phosphate dehydrogenase promoter, PGAP, is known to be a strong constitutive promoter of Pichia pastorisexpression systems that can achieve comparative expression levels with alcohol oxidase I promoter, PAOX1. Oxygen transfer strategies need to be fine-tuned in order to obtain high expression levels as P. pastorisis vulnerable to changes in oxygen transfer conditions. In this study, effect of oxygen transfer conditions on recombinant glucose isomerase production by P. pastorisunder PGAPwas studied. Two sets of experiments were conducted. In the first set, aeration rate was kept constant at Qo/V = 3 vvm and 10 vvm while agitation rate was N = 900 min-1. In the second set, dissolved oxygen concentration in the fermentation medium was kept constant at CDO= 5%, 10%, 15%, 20% and 40% air saturation while agitation rate was N = 900 min-1. The highest cell concentration was obtained as 44 g L-1at t = 9 h where CDO= 20% while the highest volumetric and specific glucose isomerase activities were achieved as 4440 U L-1and 126 U g-1cell, respectively, where CDO= 15%. Keeping dissolved oxygen concentration in the fermentation broth was kept at 15% air saturation was found to be the most advantageous with an expense of higher by-product formation and lower specific cell growth rate. Among all applied strategies, the highest oxygen transfer coefficient and oxygen uptake rates were found as KLa = 0.083 s-1and OUR = 28.9 mmol m-3s-1, respectively when Qo/V = 10 vvm and N = 900 min-1
URI
https://hdl.handle.net/11511/78278
Conference Name
Pichia 2016 Conference (2016)
Collections
Department of Chemical Engineering, Conference / Seminar
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H. Güneş and P. Çalık, “Effect of oxygen transfer conditions on recombinant protein production by Pichia pastoris under glyceraldehyde 3 phosphate dehydrogenase promoter,” 2016, p. 32, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/78278.