Produção do hormônio de crescimento bovino recombinante (rbGH) em cultivos de alta densidade

Abstract

Somatotrophin or growth hormone (GH) is a hormone synthesized and secreted by the anterior pituitary gland in all animals and their secretion is controlled by two neuropeptides: the growth hormone releasing factor (GRF), which increases GH synthesis and secretion and somatostatin (SRIF), which inhibits GH secretion. bGH has galactopoietic effect, which is known since the thirties. The mechanism of action of bGH involves a series of orchestrated changes in the metabolism of body tissues so that more nutrients can be used for milk synthesis and these changes allow the animal to achieve an increased milk yield while remaining healthy. Long term studies (10 12 weeks) demonstrated increase in milk yield up to 40% with no adverse effects in the treated cows. E. coli is currently the largest platform for expression of heterologous proteins and high cell-density culture techniques for culturing E. coli are designed to increase productivity of proteins. This system is widely used for production of various recombinant proteins available in the market. In this work were performed bioreactor cultivations using fed batch techniques, testing different feeding strategies and different IPTG induction times. At the end of the experiments the biomass obtained was 32.4 g/L using a linear feeding strategy. Approximately 2.5 mg of bGH were obtained from 1 g of wet cell using a purification protocol with only one chromatographic column.