AN ALL-GLASS APPARATUS FOR THE CONTINUOUS CULTIVATION OF YEAST UNDER ANAEROBIC CONDITIONS

Abstract

The apparatus described makes possible the production in liquid culture, under reproducible anaerobic conditions, of successive crops of yeast exhibiting a steady state of anaerobic fermentation. The apparatus should also be useful in the anaerobic cultivation of other microorganisms in liquid media. The basic features of the apparatus rest on the use of a purified inert gas (Linde "high purity dry nitrogen") not only to develop and maintain an essentially anaerobic environment but also to move fresh, oxygen-free medium into the culture chamber from a reservoir and to withdraw periodically from this chamber a liquid culture that can, without contact with atmospheric oxygen, be measured into exptl. fermentation flasks. A definite volume of culture is left in the chamber as inoculum for each charge of fresh medium. Transfers of culture or medium are effected by a positive gas pressure and are controlled precisely by a special arrangement of stopcocks. The culture chamber is held in a constant temp. bath and the culture medium in the chamber is continuously agitated by an "Alnico" bar magnet, sealed in glass, which is moved by a 2d magnet mounted on a water wheel directly below the chamber. Data are given showing the uniformity of successive yeast crops and the dry wt. per unit of cell population.