Team:Imperial College/Chassis 2


Benefits vs Challenges

Protein Expression
Secretion.PNG Single Membrane - B. subtilis is a gram-positive bacterium and contains only a single membrane. This makes B. subtilis an ideal chassis for secretion of biomaterials. Peptidase activity - B. subtilis express exopeptidases and so there is a risk that our biomaterial may be cleaved up before it can be secreted.
Foundational Technology
Gene.PNG Availability of Potential Parts - B. subtilis is a highly studied organism, with a fully sequenced genome. As a result, B. subtilis provides many useful potential parts. BioBricking - Although there is a huge number of potential parts, these still have to be manipulated to conform to existing BioBrick standards.
Starting from scratch - Although previous iGEM teams have looked at B. subtilis as a potential chassis, there are very few working B. subtilis parts available in the Registry. As a result, we will have to design a variety of promoter, ribosome binding sites and protein coding regions.
BioBrick Assembly
Integration.PNG Natural Competency and Integration - B. subtilis has been noted for its ease and efficieny of transformation. In addition, integration of exogenous DNA into the chromosome has been well studied and provides an alternative to using traditional plasmids. Vector Degradation - B. subtilis does not use all the same vectors as E. coli. One reason for this is that B. subtilis often recognises vectors grown in E. coli as foreign and digests them. Vectors and shuttle vectors are thus not reliable carriers of genetic information.
Chassis Properties
Chassis.PNG Sporulation: Transport - Under stress conditions, B. subtilis will form spores. These spores are highly resistant versions of single cells, able to withstand extreme temperatures and pH. These spores are capable of growing into new cells once favourable growing conditions are restored. Due to the resistance of spores, there is a great potential for manipulating them for transporting B. subtilis devices and constructs. Sporulation - Under stress conditions, B. subtilis will form spores. These spores are highly resistant versions of single cells. While B. subtilis itself isn't pathogenic, its spores can be damaging if inhaled. They are also highly resistant to many conditions that are used to kill cells.
High Motility - B.subtilis is often referred to as a highly motile organism in comparison to other bacterium.
Non-pathogenicity - B. subtilis is a non-pathogenic organism that is commonly found in soil. As a result, B. subtilis has a biological harzardous level of 1 and offers a useful non-pathogenic chassis for synthetic biologists.

Having decided what we're doing and how we plan to do it, all that's left is to get on with it! To see a summary of our approach and results, please continue on to our >>> Project Summary >>>