![](https://static.igem.org/mediawiki/2012/c/cf/SYSU-overview.jpg)
We have turned engineering a gene into engineering a pathway, and we have made lots of approaches to maintain stability of the whole system. In terms of cells, it is difficult to satisfy what we need if only by engineering a cell, because we require a mixture of different kinds of cells to do more complex tasks. However, it is still very difficult for us to build such a mixed system, and the priority is how to balance a suitable rate of different cell quorum. An appropriate proportion is important to the correct results and max efficiency.
To accomplish this function, we found several proteins which can inhibit E.coli replication initiation, and we also built a “quorum density inducible— bistable switch” to gain a new balance.
This system is not only useful for acquiring suitable proportion of a mixed culture quorum, but also has a great theoretical significance and application value as we proved below.