Controlling the Implementation of Transgenic Microbes: Are We Ready for What Synthetic Biology Has to Offer?

Abstract

Synthetic biology has promised and delivered on an impressive array of applications based on genetically modified microorganisms. While novel biotechnology undoubtedly offers benefits, like all new technology, precautions should be considered during implementation to reduce the risk of both known and unknown adverse effects. To achieve containment of transgenic microorganisms, confidence to a near-scientific certainty that they cannot transfer their transgenic genes to other organisms, and that they cannot survive to propagate in unintended environments, is a priority. Here, we present an in-depth summary of biological containment systems for micro-organisms published to date, including the production of a genetic firewall through genome recoding and physical containment of microbes using auxotrophies, regulation of essential genes, and expression of toxic genes. The level of containment required to consider a transgenic organism suitable for deployment is discussed, as well as standards of practice for developing new containment systems.

Figure 1:. Schematic of biological containment mechanisms.

A) Methods for addressing transfer and expression of genetic material in unintended hosts B) methods of preventing DNA from other bacteria being expressed in a transgenic strain C) methods for preventing the physical translocation of bacteria from their intended environment to an unintended environment, and D) methods for removing bacteria from their intended environment if they are no longer required. Physical forms of containment such as barriers and waste management are not included.