For instance, protein concentration by extraction into two phase systems combined with clarification and purification can be done together.
Proteins are highly susceptible for loss of biological activity; hence their formulation requires special care. It is basically an analytical technique dealing with the separation of closely related compounds from a mixture.
For example, expanded bed adsorption Vennapusa et al. Supercritical fluid extraction is rather expensive, hence not widely used SCF has been used for the extraction of caffeine from coffee beans, and pigments and flavor ingredients from biological materials. The cylinder is fitted with glass beads.
For most products, water is the chief impurity and isolation steps are designed to remove most of it, reducing the volume of material to be handled and concentrating the product. As the drum rotates, it picks up the biomass which gets deposited as a cake on the drum surface.
Advantages of downstream processing
Flocculation: In flocculation, the cells or cell debris form large aggregates to settle down for easy removal. The efficiency of extraction is dependent on the partition coefficient i. The stationary phase is the porous solid matrix packed in a column equilibrated with a suitable solvent on to which the mixture of compounds to be separated is loaded. Membranes used in filtration are made up of polymeric materials such as polyethersulfone and polyvinyl di-fluoride. Increase in temperature: The heat sensitive proteins can be precipitated by increasing the temperature. In Table Product isolation is the removal of those components whose properties vary considerably from that of the desired product. Some of the important types of evaporators in common use are briefly described. Centrifugation: The technique of centrifugation is based on the principle of density differences between the particles to be separated and the medium. The different types of chromatography techniques used for separation mainly proteins along with the principles are given in Table They reduce the dielectric constant of the medium and enhance electrostatic interaction between protein molecules that lead to precipitation. In Fig. Falling film evaporators: In this case, the liquid flows down long tubes which gets distributed as a thin film over the heating surface.
In ion-exchange chromatography, the pH of the medium is very crucial, since the net charge varies with pH. Ion-exchangers are of two types cation- exchangers which have negatively charged groups like carboxymethyl and sulfonate, and anion- exchangers with positively charged groups like diethylaminoethyl DEAE.
Downstream processing in fermentation slideshare
The cells break as they are forced against the wall of the vessel by the beads. The selection of a particular method depends on the nature of the cells, since there is a wide variation in the property of cell disruption or breakage. Spray drying: Spray drying is used for drying large volumes of liquids. The vacuum can now be released and the product containing vials can be sealed e. Freeze-drying: Freeze-drying or lyophilization is the most preferred method for drying and formulation of a wide-range of products—pharmaceuticals, foodstuffs, diagnostics, bacteria, viruses. For certain small molecules, antibiotics, citric acid , formulation can be done by crystallization by adding salts. As the drum rotates, it picks up the biomass which gets deposited as a cake on the drum surface. However, due to high cost, it is not suitable for large-scale use in industries. Purification by Chromatography: The biological products of fermentation proteins, pharmaceuticals, diagnostic compounds and research materials are very effectively purified by chromatography. They form complexes with oppositely charged protein molecules that causes charge neutralisation and precepitation. It has been successfully used for breaking E. The equipment is simple with low power consumption and is easy to operate.
based on 99 review