The advantages of using stirred tank bioreactors over shake flasks are:

i) It has an agitator system for better mixing of oxygen.

ii) It has an oxygen delivery system to deliver fresh oxygen for the cells in the bioreactors.

iii) It has a foam control system to avoid frothing and degeneration of the required product.

iv) It has a temperature and pH control system to maintain optimum growing conditions for the cells.

v) It also has sampling ports so that small volumes of culture can be withdrawn periodically to avoid over population of the cells and overflow of reaction mixtures when new batches are added.