The two-phase partitioning bioreactor is usually applied in many bioprocesses for enhancing the productivity. The controlled substrate delivery from the non-aqueous phase to aqueous phase opens a new area of application of this strategy for enhancing the substrate solubility and eliminating the substrate inhibition of bioprocesses, such as bioconversion, biodegradation, etc. The extraction product from bioreaction phase has advantages over conventional media, such as removing the product inhibition on the microorganism, protecting the product form further degradation and cutting down the effluent treatment costs as a result of the use of a more concentrated feedstock. This article examines recent research on methods of the two-phase partitioning bioreactor. The practical potential of cloud point system as a novel two-phase partitioning bioreactor is illustrated by reference to a particular bioconversion, namely the side-chain cleavage of cholesterol to produce a pharmaceutical intermediate androsta-diene-dione (ADD).