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Team:Groningen/Template/MODULE/project/parts
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Detection system
We want Lactococcus lactis to start producing growth inhibiting molecules only when a pathogen is present. Therefore, L. lactis must be able to sense Pseudomonas aeruginosa and Staphylococcus aureus.
Detecting Pseudomonas aeruginosa
To give Lactococcus lactis the ability to detect P. aeruginosa we assembled a new BioBrick. We adopted a widely used principle for detection, namely detection of quorum molecules. P. aeruginosa produces AHLs for communication1, therefore we have built an AHL sensor) that can be used by L. lactis.
To test the how well Lactococcus lactis can detect P. aeruginosa we build a construct which has the AHL sensor ability coupled with a GFP gene.
A related part that was made is the AHL generator. Many iGEM teams are working with AHL sensing, either to detect P. aeruginosa or for an regulatory mechanisms. Our AHL generator produces AHLs, which enables other teams to produce AHLs and test their sensors without the hassle of working with the pathogenic bacterium itself.
Secretion system
Infection by Staphylococcus aureus and Pseudomonas aeruginosa will be battled by Lactococcus lactis using molecules that prevent biofilm formation, disrupt communication between pathogens and kill the pathogen.
Antibiofilm formation
When bacteria start infection of a wound, they often protect themselves with a biofilm. For an effective fight against these infections, the biofilm should be broken down. We have assembled a BioBrick of dispersinB fused to an USP45tag. This part was later assembled in the secretion system, and can work against S. aureus and P. aeruginosa .
Battling Pseudomonas aeruginosa
We will fight against P. aeruginosa with an dual action system, consisting of the new BioBricks dispersinB and aiiA. DispersinB works against biofilm formation as described above. AiiA is an quorum quenching enzyme which disrupt communication between P. aeruginosa. By disrupting communication we try reduce the activity of both dividing and activation of pathogenic genes by P. aeruginosa.2
Battling Staphylococcus aureus
The cell wall of the Gram-positive bacterium S. aureus contains Lipid-2 fatty acids. These are perfect targets for the anti-microbial nisin.3 We designed and assembled nisin in an a novel BioBrick that combines the expression of dispersinB and nisA. With this second dual action system, we want to fight of infections by S. aureus.
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