The survival of bacteria is associated with the ability to respond to changing environmental conditions. For example, during situations of environmental pressure (e.g. UV, heat, or drug exposure) ROS levels can increase, leading to damage of DNA, lipids and an initiation of signaling events that can lead to cell death. Fortunately, bacterial possess enzymes such as superoxide dismutase (SOD) and catalase enzymes, as well as other antioxidant agents that can reduce ROS. However, when the balance between the production and elimination of ROS is upset, it can have unwanted effects. Thus, the ability of bacteria to increase their tolerance to ROS would be beneficial to the cell’s survival.
Researchers at UC San Diego have developed set of bacterial strains with defined mutations that have been selected to tolerate large amounts of Reactive Oxygen Species (ROS) stress. These strains are useful as platform strains because they can be used as starting chassis for generating a bioproduction strain where tolerance to such stress is desirable. These strains (and the mutations that enable their phenotype) tolerate a great deal of ROS stress and still function and grow robustly. A number of molecules of interest involve pathways that generate significant levels of ROS stress and cripple most strains. Thus, these strains would be able to tolerate such pathways than other starting chassis available
The ROS tolerant strains can be used as platform strains to generate a number of products at high rates and titers with additional genetic modification. In addition, the mutations in the ROS tolerant strains can be reintroduced into additional strains to potentially engineer these ROS tolerant phenotypes in E. coli strains, as well as other species
The ability of bacteria to increase their tolerance to ROS would be beneficial to the cell by allowing it to tolerate environmental stressors and promote survival.
The ROS tolerance strains have been selected in vivo and exist as frozen stocks in glycerol at -80C. The mutations which enable the phenotypes are also defined. These strains can be cultured and grown from these stocks and they have been demonstrated to retain their growth characteristics, i.e. a high ROS stress tolerance. The strains are a physical living single cell organisms.
The technology is patent pending and available for licensing.
ROS, environmental stressors, survival, cell death, bacterial adaption