the present invention provides a novel apparatus to grow cells where the cultivation chamber is partially filled with liquid cultivation medium and cells . mixing and aeration is achieved by generating intermittently one single large gas bubble at the bottom of the column bioreactor , the single large bubble width representing from 50 to 99 % of the tank width , preferably from 60 to 99 %, more preferably 98 . 5 %. the culture medium flows out as a film between the large bubble and the inner wall of the bioreactor . this rising bubble allows mixing and aeration of the bulk . as the design of the invention is very simple , it is possible to manufacture it with flexible plastic material and use the apparatus as a disposable system . moreover , such a mixing / aeration principle minimizes cell damages usually due to shear stress and small bubbles and allows easy and efficient scale - up from small scale to a larger one . such a large - scale , efficient and disposable culture system can largely reduce production costs .