| Autor: |
J. Colin Slaughter, E. Linus C. Okafor, Emmanuel E. Egbosimba |
| Rok vydání: |
1988 |
| Předmět: |
|
| Zdroj: |
Journal of the Institute of Brewing. 94:249-252 |
| ISSN: |
0046-9750 |
| DOI: |
10.1002/j.2050-0416.1988.tb04581.x |
| Popis: |
When glucose was used as the energy source in the assay, the perceived ammonium permease activity of Saccharomyces cerevisiae NCYC 1108 remained relatively unchanged in yeast samples taken throughout the main period of fermentation of a malt extract medium. This was in contrast to the earlier work on the fermentation of a defined glucose/salts medium where the specific ammonium permease activity rose rapidly as fermentation proceeded. The present data suggest that the level of ammonium permease activity of cells fermenting a malt extract medium was low due to nitrogen catabolite repression and that inhibition of the carrier system was important in determining the actual rate of uptake from the medium. When ammonium permease in cells from a malt extract medium was assayed using maltose, essentially similar results were obtained. However, the actual values were lower and the results suggested that at some points during the fermentation the ability of the cells to take up maltose during the assay was an important factor in determination of the perceived ammonium permease activity. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
Plný text