Extractive fermentation in aqueous two-phase systems is a meaningful approa
ch to overcome low product yield in a conventional fermentation process, an
d by proper design of the two-phase system it is possible to obtain the pro
duct in a cell-free stream. The characteristics of an aqueous two-phase sys
tem, various polymers used for forming an aqueous two-phase system, the phy
sicochemical parameters of the aqueous two-phase system, partitioning of bi
omolecules and cell mass and the effect of individual phase forming polymer
s on cell growth and product formation are reviewed in this article. The va
rious extractive fermentation processes are also summarised here. At the en
d, the economic viability and scope of aqueous two-phase fermentation are b
riefly discussed in relation to the wider application of this topic.