Presentation given by the Cornell iGEM team at the Cornell SILS research symposium

1. Genetic engineering of E.coli for heavy
metal sequestration
By Jonlin Chen and Aaron Gittelman

2. The Team
● Award-winning
undergraduate project
team
● International Genetically
Engineered Machine
● “Biobricks” : Standardized
genetic parts
● Annual competition

3. Water Contamination
● Heavy metals
o Mercury, lead, nickel
● Sources:
o Industrial manufacturing
o Hydraulic fracturing
o Coal mining
o Construction
● Harmful to humans, ecosystem, aquatic life
o Biomagnification

4. Project Goals
● Engineer E.coli to uptake heavy metals from
the environment
● Integrate cells into a continuous water
filtration system
● Test efficacy of biological filter with lab
based and local water samples

5. Heavy Metal Transport Proteins
● Proteins specific to heavy metals
o nixA - nickel
o merT and merP - mercury
o CBP4 - lead
● Behind the constitutive Anderson promoter
nixA
Anderson
Promoter

6. E.coli - Metal Transport
E.coli
Metal Ions
Transport
Protein

7. Metallothioneins
● Low molecular weight proteins
● High metal binding affinities
o GST-YMT, GST-PMT
● Expression causes cellular dormancy
● Arabinose inducible system
Arabinose
araBAD Promoter
Metallothionein
T7 Promoter
T7 Polymerase

8. Metallothionein Expression
E.coli
Metal Ions
Transport
Protein
Metallothioneins

9. Saturation Sensing System
● Insert mRFP gene behind metal-inducible
promoters
o Cells will fluoresce when metallothioneins are
saturated
● Metal sensitive promoters induced once MT
are saturated
mRFP
Metal Inducible Promoter

10. Reporter System
E.coli
Metal
Ions
Transport
Protein
Metallothioneins
Reporter Plasmid

11. Efficacy Analysis and Applications
● Growth Assays
● Fiber Reactor Filter Testing
■ Lab made samples
■ Local water supplies
● Further applications
○ Buoys
○ Factory waste water treatment

12. Thank you for coming!
● Special thanks to
o Cornell University
o College of Engineering
o Wilson Lab
o Dr. Shivaun Archer
o Dr. Xiling Shen