ICAR Research Data Repository for Knowledge Management

Recently, efforts are in progress by research and industrial community for the production of biological products through the application of biotechnology. However, the technology for downstream processing (DSP) of biomolecules from the broth has not kept pace with the advances in the upstream operations, despite the fact that in many cases DSP contributes major share (50-80%) of the total production cost. Existing DSP techniques such as chromatography, electrophoresis, precipitation etc., pose scale-up problems, and are prohibitively expensive on large-scale, unless the product is of high value. Therefore, current research in the area of DSP is directed towards the development of efficient and scaleable alternative bioseparation processes with flexibility for continuous operation.Aqueous two-phase extraction (ATPE) has been recognized as superior and versatile technique for DSP of biomolecules. A wealth of information has been reported in the literature on various aspects of ATPE for the isolation and purification of proteins/enzymes and other biological
materials. ATPE offers a better alternative to the existing methods of primary purification, providing low space-time yield, better enrichment of product, ease of scale-up and flexibility for continuous operation. This technique is
effective also in removal of by-products such as other undesirable enzymes/proteins, unidentified polysaccharides and pigments. Furthermore,application of ATPE permits easy adoption of the equipment and the methods of conventional organic-aqueous phase extraction used in the chemical industry. ATPE is recognized as a primary purification step in the overall protein recovery train, since it is not selective enough to provide the desired purity of the enzyme/protein. Use of ATPE enables the desired product (enzyme/protein) to partition into one of the phases, thus reducing the volume of the process stream to be handled during the subsequent purification steps. Hence, final purification can be accomplished by highly selective techniques such as chromatography, electrophoresis.
After successfully partitioning the biomolecule to one of the phases in ATPE, it is desirable to separate the phase forming components and concentrate the solution containing the biomolecules. Membrane processes such as ultrafiltration (UF), dialysis can effectively do this job. The integration of ATPE with any one of the above membrane processes holds considerable promise to increase the productivity of the overall process.