Melbourne/Gas vesicles
From 2007.igem.org
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Neutral buoyancy is required to overcome settling that would occur more rapidly than the photo exposure system could operate. Based on Maura Cannons work we would expect the bacteria without vesicles to settle out within 16 hours. Based on the 2005 IGEM Coliroid days of exposure to light was required even with an enzymatic output stage. Maura Cannon guarantees three days of vesicle stability.
Expressible gas vesicles also have applications in floatation processes, bioremediation, biomining, and as an alternative, more energy efficient, form of movement and in control of photo damage by positioning bacteria at a fixed depth in water.
In 1998 Maura Cannon and Ning Li expressed gas vesicles from Bacillus Magaterium in E.cloi. The expression was highest with extracted plasmid pNL29 (pBluscriptIIKS expression plasmid) which Maura Cannon has kindly made available to us. The plasmid contains a 6Kb cluster of 11 genes . At its simplest the gene cluster would need to be placed biobrick so that it can be driven by POPS entry. This Strategy is the lowest risk as others have had difficulties with occlusion bodies forming.
Contents |
Gas Vesicle Background
Method
Possible extensions:
- Determine proteins in vesicles and hence relevant genes:
- Perform 2DGE on expressed vesicle proteins.
- Seperate vesicles by floatation and do an SDS PAGE.
- Apply MALDI TOF MS to determine Amino acid sequences and hence degenerate code and genes.
- Seperate coding regions into individual biobricks.
- Recombine in different ways and observe effect on gas vessicle structure.
Knock out/modify some of the genes to observe the effect on vesicles and buoyancy, aiming to improve lifting speed and capability of cells.
