 In this module we will again talk about the purification strategies. As we have discussed that in downstreaming process the first is depending upon the localization of the product we use the separation techniques either the centrifugation or filtration. So, there are different choices of centrifugation either that is batch centrifuge either that is a continuous centrifugation and on other hand there is filtration techniques either we use the simple filtration technique either we use the we can say that rotary vacuum filters either we use the filter press there are different filtration techniques are available. So, after the separation of the two phases two fraction then there is a purification. So, the isolation and that depend upon the chemical nature of the product by using some organic solvents recovery method use of some chromatographic techniques either we can use the ultra purification steps ultra filtration steps. So, when there is a recovery when we recovered our product that is mostly in a aqueous film mostly that is in the form of the soluble solution. So, that contain a diluted form. So, then the possible way in the recovery and the purification is then in order to get the product in a purified form. So, then there is a further step then is the drying of the product. So, as concerned the drying of the product that depend upon directly the nature of the product if the product is heat level then we have to use those drying method which not effect the product. So, if the product is not sensitive to the temperature we can use some other drying techniques. So, there are two either is that low temperature drying method either that is a high temperature that about 120 degree Celsius. So, as concerned the drying process which we called as the biological product that can be the enzyme that can be any Acer's that can be any Amino Acer's. So, that is often the last stage of the manufacturing process. So, if we manufacture our product then there is a drying. So, it involve the final removal of the water from the heat sensitive material ensuring that there is a minimum loss of the viability and the activity of the and the quality value of our product which if that is used in any food or in any then we can say that maintain the nutritional value of that product. So, drying is undertaken because the cost of the transport can be reduced and the second is the material is easy to handle and package. So, the material can be stored more conveniently in a dry state just to increase the shelf life. So, it is important that as much water as possible is removed initial by centrifugation or in filter press to minimize the heating cost in the drying process, but when this process we cannot apply then there is the only choice of the either that is the a spread drying you can see in this that how the spread drying is act, but in this spread drying we have the feeding on one side and that is spray inside where is the hot air having the movement and then hot air exit and then the dried particles settled down and we collect the product. So, then if the heat sensitive material then is the choice of the freeze drying. So, the freeze drying method when there is basically in a sublimation techniques. So, the first the material is having solidify and then at a very low vacuum and a very under negative pressure and a very low temperature then the water has to remove. So, that is the method which is mostly used for the enzymes and some other heat mobile heat sensitive product of fermentation. So, the final process of the purification is the drying just to minimize the size and to increase the shelf life before the packaging of that product. So, as concern the whole summary of the recovery at the purification it is just a summary of that. So, starting from the process of the separation then the some chemical methods then lastly come is a drying techniques.