fermenter

Fermenter \Fer*ment"er\, n.
   an apparatus for carrying out {fermentation} by a liquid
   suspension of microorganisms; a fermentation tank; as, an
   industrial fermenter.

   Note: Laboratiory and industrial fermenters are usually
         equipped with a means of stirring the contained liquid
         so as to avoid settling of the fermenting organisms,
         and often have other, sometimes elaborate, mechanisms
         to control conditions of the fermentation, such as
         temperature, degree of aeration, or pH. The main
         structures of large industrial fermenters are typically
         made of steel.
         [PJC]