Amino acid supplementation, controlled oxygen limitation and sequential double induction improves heterologous xylanase production by Pichia stipitis

Date
2005
Authors
Gorgens J.F.
Passoth V.
Van Zyl W.H.
Knoetze J.H.
Hahn-Hagerdal B.
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Heterologous endo-β-1,4-xylanase was produced by Pichia stipitis under control of the hypoxia-inducible PsADH2-promoter in a high-cell-density culture. After promoter induction by a shift to oxygen limitation, different aeration rates (oxygen transfer rates) were applied while maintaining oxygen-limitation. Initially, enzyme production was higher in oxygen-limited cultures with high rates of oxygen transfer, although the maximum xylanase activity was not significantly influenced. Amino acid supplementation increased the production of the heterologous endo-β-1,4-xylanase significantly in highly aerated oxygen-limited cultures, until glucose was depleted. A slight second induction of the promoter was observed in all cultures after the glucose had been consumed. The second induction was most obvious in amino acid-supplemented cultures with higher oxygen transfer rates during oxygen limitation. When such oxygen-limited cultures were shifted back to fully aerobic conditions, a significant re-induction of heterologous endo-β-1,4-xylanase production was observed. Re-induction was accompanied by ethanol consumption. A similar protein production pattern was observed when cultures were first grown on ethanol as sole carbon source and subsequently glucose and oxygen limitation were applied. Thus, we present the first expression system in yeast with a sequential double-inducible promoter. © 2004 Federation of European Microbiological Societies. Published by Elsevier B.V. All rights reserved.
Description
Keywords
alcohol, amino acid, carbon, endo 1,4 beta xylanase, glucose, oxygen, xylan endo 1,3 beta xylosidase, aeration, alcohol consumption, cell culture, cell density, conference paper, controlled study, enzyme activity, enzyme synthesis, nonhuman, oxygen transport, Pichia stipitis, promoter region, protein synthesis, Aerobiosis, Amino Acids, Anaerobiosis, Culture Media, Ethanol, Fermentation, Gene Expression Regulation, Fungal, Oxygen, Pichia, Promoter Regions (Genetics), Recombinant Proteins, Xylan Endo-1,3-beta-Xylosidase
Citation
FEMS Yeast Research
5
07-Jun