Streptomyces - Biotechnology

Biotechnology

In recent years, biotechnology researchers have begun using Streptomyces species for heterologous expression of proteins. Traditionally, Escherichia coli was the species of choice to express eukaryotic genes, since it was well understood and easy to work with. Expression of eukaryotic proteins in E. coli may be problematic however, due to the inability of bacteria to glycosylate proteins. And there may also be issues with incorrectly folded proteins, which may lead to insolubility, deposition in inclusion bodies, and loss of bioactivity of the product. Though E. coli have secretion mechanisms, these are of low efficiency and result in secretion into the periplasmic space, whereas secretion by a Gram-positive bacterium such as a Streptomyces sp. results in secretion directly into the extracellular medium. In addition, Streptomyces spp. have more efficient secretion mechanisms than E.coli. The properties of the secretion system is an advantage for industrial production of heterologously expressed protein because it simplifies subsequent purification steps and may increase yield. These properties among others make Streptomyces spp. an attractive alternative to other bacteria such as E. coli and Bacillus subtilis. As is true for all bacteria, Streptomyces spp. do not have the ability to glycosylate proteins, which may necessitate using a eukaryotic host, if this is required for bioactivity of the product.