Physiological characterization of xylose metabolism inAspergillus niger under oxygen-limited conditions
| Autor: | Jens Nielsen, Lisbeth Olsson, Gianni Panagiotou, Susan Lisette Meijer |
|---|---|
| Rok vydání: | 2007 |
| Předmět: |
Xylose
biology Metabolite Citric Acid Cycle Aspergillus niger Succinic Acid Primary metabolite Bioengineering Metabolism Xylitol biology.organism_classification Applied Microbiology and Biotechnology Aerobiosis chemistry.chemical_compound Bioreactors chemistry Xylose metabolism Biochemistry Arabitol Anaerobiosis Biotechnology |
| Zdroj: | Biotechnology and Bioengineering. 98:462-475 |
| ISSN: | 1097-0290 0006-3592 |
| Popis: | The physiology of Aspergillus niger was studied under different aeration conditions. Five different aeration rates were investigated in batch cultivations of A. niger grown on xylose. Biomass, intra- and extra-cellular metabolites profiles were determined and ten different enzyme activities in the central carbon metabolism were assessed. The focus was on organic acid production with a special interest in succinate production. The fermentations revealed that oxygen limitation significantly changes the physiology of the micro-organism. Changes in extra cellular metabolite profiles were observed, that is, there was a drastic increase in polyol production (erythritol, xylitol, glycerol, arabitol, and mannitol) and to a lesser extent in the production of reduced acids (malate and succinate). The intracellular metabolite profiles indicated changes in fluxes, since several primary metabolites, like the intermediates of the TCA cycle accumulated during oxygen limitation (on average three fold increase). Also the enzyme activities showed changes between the exponential growth phase and the oxygen limitation phase. In general, the oxygen availability has a significant impact on the physiology of this fungus causing dramatic alterations in the central carbon metabolism that should be taken into account in the design of A. niger as a succinate cell factory. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Plný text