Biosynthesis of bovine growth hormone in Escherichia coli DH1 cells and its purification on a pilot scale

: The biosynthesis of the bovine growth hormone (BGH) in E. coli DH1 cells containing the plasmid pbGH(1-119)ptrp was studied. It was found that BGH accumulated in the cytoplasm of bacterial cells as optically dense granules that can be isolated by low-speed centrifugation. A fraction of purified protein granules was used for further purification of BGH. A purified BGH preparation contained two polypeptides with molecular weights of 18,000 and 22,000 D. The state of plasmid was investigated during cultivation and storage of the culture.