Einstellbare Gaszufuehrung fuer einen Fermentationsreaktor

The invention relates to an adjustable gas supply which is arranged on the floor of a fermentation reactor and is used in an Airlift-Schlaufen reactor in order to permit no disturbances in the process by any reduction in gas supply and to render gas feed and dispersion adjustable. The gas flow can thus be fed through at least one drill hole (2) on whose side projecting towards the inside of the reactor there is a gas oulet gap, and a shaft (5) pretensioned against the gas pressure and provided with a sealing element (4) to seal the gas outlet gap (3) is inserted through the drill hole (2).