Dissolved oxygen concentration affects the accumulation of HIV-1 recombinant proteins in Escherichia coli

A central problem in aerobic growth of any culture is the maintenance of di ssolved oxygen concentration (DOC) above growth-limiting levels especially in high-cell density fermentations that are usually of the fed-batch type F ermenter studies have been conducted to determine the influence of DOC on t he production of heterologous proteins in Escherichia coli. The results dem onstrated that there is a significant degree of product-to-product variatio n in the response of heterologous protein accumulation to DOC. For translat ional fusions of the human immunodeficiency virus-1 (HIV-1) proteins p24Gag and Env41, the imposition of a dissolved oxygen (DO) limitation resulted i n 100 and 15% increases in the respective product yields. On the other hand , the imposition of a DO limitation had no effect on the production of a si milar translational fusion of the HIV-1 protein p55Gag, and a large negativ e effect on the production of an influenza protein (C13). The stimulatory e ffects of DOC on p24Gag production were investigated further. The results o f my studies suggested that the stimulatory effect observed at reduced agit ation rates on p24Gag accumulation was owing to an oxygen effect and not a shear effect. Furthermore, the results of my investigations indicated that the effect a DOC had on the production of p24Gag was strongly influenced by the cell density at which the culture was induced.