biological elements have the number and function that restrict the development of synthetic biology . Transforming and optimizing existing components through directional evolution is an important and key platform technology in the field of synthetic biology. Traditional directional evolution methods require a lot of human labor and repeated operations. Against this background, Harvard University developed Phage-Assisted Continuous Evolution (PACE), which can realize automatic connection and iterative cycles of library construction and screening, significantly improve evolutionary efficiency, and is an important milestone breakthrough in the development of directional evolution technology. However, there is currently a lack of a simple directional evolution technique/method that can be used to evolve multiple targets simultaneously, and PACE's demand for complex fluid control devices and detection equipment limits its extensive development in ordinary laboratories.
Recently, Shenzhen Advanced Technology Research Institute of Chinese Academy of Sciences Liu Chenli's research group and Fu Xiongfei's research group jointly published an article titled "Exploiting spatial dimensions to enable parallelized continuous directed evolution" on "Molecular Systems Biology" . This work quantitatively studied the dynamic process of spatial co-growth and migration of bacteria- phages, and based on this quantitative understanding, the spatial phage-assisted continuous directional evolution system (Spatial Phage-Assisted Continuous Evolution, SPACE). The development of the SPACE system was inspired by Liu Chenli's research team on bacterial migration and colonization (Nature, 2019, 575: 664-668). The team discovered that the growth and movement state of bacteria in the process of spatial expansion is similar to a "mobile chemist ".
This project research team originally used this "mobile chemist" to replace the continuous culture device required for the continuous amplification of bacteriophages in the PACE system, thereby greatly simplifying the system. The team constructed an experimental system for bacteria-phage co-migration and used theoretical models combined with experimental evolution to analyze the evolutionary dynamics of phage infection hosts during bacterial migration. Based on the above quantitative understanding, the team built the SPACE system by designing and transforming key functional modules such as bacteriophage replication packaging and inducing mutations. The research team used this system to evolve the ability of T7 RNA polymerase to recognize random promoter sequences in parallel. The SPACE system is simple, efficient, and visualized, and has the platform capability of large-scale optimization and transformation of biological components. This work is an example of quantitative synthetic biology research that starts from basic theory, rationally designs and constructs life systems, and ultimately extends to engineering applications. In the future, the research team will use SPACE, a platform technology, to evolve a series of important biological macromolecules applied in the fields of medicine, agriculture, chemicals, etc., and strive to solve practical problems in scientific research and industry.
Figure description: Application prospect diagram of the spatial phage-assisted continuous evolution system (SPACE system)
Source: Photo provided by the research team
Article link:
https://doi.org/10.15252/msb.202210934
