Downstream processing is a bioprocess. Broadly speaking, it is a method to extract biosynthetic materials from organic and natural sources. The process involves purification and recovery.
Downstream processing is an area of special interest in the field of Chemical Engineering. This method was devised mainly because the commonly used product separation methods (like distillation) could not guarantee the stability of the bio molecules.
Biosynthetic products refer to those products that are born out of a bio-process. These products include proteins, cells, antibiotics etc. Various techniques are involved in the process of purification and recovery so as to extract the maximum amount of product possible.
Since the size and constitution of the products vary, different purification and isolation methods are employed. The methods chosen depend on the degree of sensitivity and cost.
This process generally occurs after fermentation in most cases and is move cost laden than Upstream Processing.
The various stages involved in Downstream Processing:
The process is roughly divided into four stages:
- The first stage involves the removal of all soluble particles from the culture medium or culture broth. This includes several processes of filtration, sedimentation, flocculation etc.
- The second stage includes separation of the desired product from the medium or putting it in another way, the separation of unwanted components from the product.
- The third processing is one of purification. It entails removing impurities from the desired product. This process requires sensitive apparatus so that the fine contaminants are isolated.
- The final process involves maintaining the stability of the extracted product and preserving it. This would also include packaging methods.
Some of the well-known applications of downstream processing would be in the field of biotechnology, particularly DNA recombination, in the food processing industry for preservation and pharmaceuticals to produce antibiotics, hormones etc.