Why is recombinant protein so called ? How can it be harvested on a large scale ? Write two precautions to maintain a higher yield. (3 marks)
Recombinant protein. Gene coding for protein is expressed in heterologous host, so it is known as recombinant protein.
To produce large quantities of recombinant protein, bioreactors are used.
Bio-reactor and its working :
(i) It consists of large vessels in which new materials are biologically converted into specific
products by microbes, individual enzymes of microbial plant and animal or human cells.
(ii) The bioreactor provides optimum growth conditions like temperature, pH, substrate, salts, vita-
mins and oxygen to get desired products.
(iii) The most commonly used bioreactor is of stirring type.
(iv) A stirred tank consists of a cylindrical vessel or a vessel with a curved base to facilitate mixing
of the contents.
(v) Bioreactor has an agitator system, an oxygen delivery system, a foam control system, a tem-
perature control system, pH control system and sampling ports so that small volumes of the
culture can be withdrawn easily.
(i) There should be a constant mixing of the reactor contents.
(ii) There should be oxygen availability throughout the bioreactor.