DISPOSABLE BIOREACTOR BAGS- ANY TAKERS?

It is not surprising that sooner or later some one or some fermentation technologists will come up with the idea of inventing 'disposable bioreactors' in this age of convenience and take aways and disposables. The idea is not new and have been in the minds of most fermentation technologists. It is only the question of:

1 What sort of fermentation is suitable for the kind of fermentation that can be carried out using disposable bioreactors?
2 What advantages do we get by using the disposable fermentors compared to the traditional and widely accepted stainless steel CSTRs?

At present the use of disposable fermentor bags are used only in small scale cultivation of mammalian cells and biologics in pharmaceutical and biotechnology companies.

There are several advantages and disadvantages in using these disposable bioreactor bags.
In terms of advantages these disposable bags are manufactured under sterile materials and under clean room environment. There is no need for cleaning processes and thus will shorten downtime and turn around time. As new bags are always used for each fermentation run there is lower risks of cross contaminations

The main disadvantage faced in using these disposable fermentors are scaling up of the production process. Comparing to CSTR with well established hydrodynamic characteristics which makes it easy for scaling up, disposable bioreactors hydrodynamics are unchartered territories

Maybe in the future this problem of scaling up the disposable bioreactors will be overcome. Since these disposable bioreactors are for single use and made of expensive plastics, there is the need to buy a large number of these bioreactors.

LIMITATIONS OF DISPOSABLE BIOREACTOR BAGS
--------------------------------------------------------
In essence the disposable bioreactor bags are just specialised plastic bags that are used to carry out fermentations. It fulfill the basic criteria of the fermentor but it does face limitations such as:

1 The type of mixing that can be carried outt in the disposable bioreactor bags. The bag will only only have to depend on simple mixing such as provided by the ' rocking mixing' and is not capable of a more powerful shearing mixing as seen in conventional bioreactors. Maybe this kind of mixings are more suitable for the fermentation of animal or plant cells? Less shear forces

Then there is the question of sensors. Sensors are expensive and could not be regarded as disposable item thrown away after every fermentation. These sensors could be re used again after sterilizations in the disposable plastic bags

Thus for the moment we can safely say that these disposable bioreactor bags are suitable for low volume high value fermentation