HSA is a main component of plasma proteins and is used in pharmaceutical preparations for the treatment of massive hemorrhage, shock, burn injury, hypoproteinemia, fetal erythroblastosis and the like.
Currently, HSA is produced mainly as a product from fractions of collected blood. However, such a production process is economically disadvantageous, and the supply of blood is sporadic. In addition, blood itself is also problematic in that it often contains undesirable substances such as hepatitis virus.
In order to solve such problems, attempts have been made to produce HSA by fermentation of microorganisms in which the HSA gene was introduced, thereby making use of the recently developing recombinant DNA techniques. However, even such recombinant DNA techniques cannot give satisfactory results in terms of the industrial mass production of HSA.
As a consequence, great concern has been directed toward the establishment of an industrial process for producing recombinant HSA in a large amount with a low cost.