Team
Chem
Biological Water Filtration
Purification Process
• Add cells to possibly contaminated water
• Cells take in arsenic and store it
• Cells provide an output (color) signaling
the water is clean or needs further
processing
• Separate of cells from water
• Possibility for further processing
Devices
• 2 Arsenic Sensors
– Sensitive: activated by any arsenic
– Non-sensitive: activated by maximum
tolerable arsenic level
• 2 Color Generators
• Arsenic Transport and Storage Device
Arsenic Transport and Storage
Remove the
gene that
encodes this
transport
protein
Arsenic
Measurement
Tripathi, R.D., Srivastava, S., Mishra, S., Singh, N., Tuli, R.,
Gupta, D.K. and Maathuis, F. Arsenic Hazards: Strategies for
Tolerance and Remediation by Plants. Trends in
Biotechnology. 2007, 25.4, 158-165.
Device Level Diagram
Where is
Concentration
Read?
Outside
Vacuole
Sensitive
Arsenic
Sensor
Color Generator 1
(constitutively active)
Arsenic Transport and
Storage Device
(constitutively active)
Inside
Vacuole or
with a Timer
NonSensitive
Arsenic
Sensor
Color Generator 2
Simulation: Pure Water
Sensitive
Arsenic
Sensor
Green Color Generator
(constitutively active)
Arsenic Transport and
Storage Device
(constitutively active)
NonSensitive
Arsenic
Sensor
Red Color Generator
Result: Cells Stay Green → Separation
Simulation: Maximum Arsenic
Sensitive
Arsenic
Sensor
As
As
NonSensitive
Arsenic
Sensor
Green Color Generator
(constitutively active)
MAXIMUM
Arsenic
Transport and
Storage Device
ARSENIC
(constitutively active)
Red Color Generator
Result: Cells Turn Red → Separate and Process Again
Timing Diagram: Maximum Arsenic
1
Green Color
Generator 0
Sensitive 1
[As] Sensor
0
Transport 1
and Storage
0
Non1
Sensitive
[As] Sensor
0
Red Color
Generator
1
0
t=0
No Arsenic
Contaminated
Water Added
Midlevel [As]
Maximum [As]
Timing Diagram: Midlevel Arsenic
1
Green Color
Generator 0
Sensitive 1
[As] Sensor
0
Transport 1
and Storage
0
Non1
Sensitive
[As] Sensor
0
Red Color
Generator
1
0
t=0
No Arsenic
Contaminated
Water Added
Midlevel [As]
Maximum [As]
Biological Parts
Background System
ARR1
ARR2
Biological Parts
Control System
P(x)
YCF1
[As]
[As]max
P(y)
P(z)
GSH1
GCGD:
BBa_K27400
4
RCGD:
BBa_K2741
00
YRepressor
XRepressor
Cellular Chassis
[Source:http://www.botany.hawaii.edu/nlc_biology/1406/lab/r2/slide6.jpg]
[Source: http://www.ppws.vt.edu/scott/weed_id/eldde.htm]
Testing/Debugging
• Cell Death
– Effectiveness of
ARR1, ARR1, YCF1,
GSH1
• Need to determine
Vacuole limits
• Testing Color
Generators
• Promoter Design
[Source: http://www.sciencephoto.com/images/]
Global Impacts
Impacts
If this process succeeds:
• Solves one of the most problematic issues
of the developing world, saving millions of
lives.
– 70 million people are affected in Bangladesh
alone - arsenic in ground water is the cause of
23% of all the deaths there!
Why Biological Water Filtration by
Team Chemistry?
• No energy requirement (operates
independent of electricity)
– Accessibility to effective water filtration
technology even in rural parts of the developing
world
• Very low cost of sustaining system
• The end product is not a waste
– Possibility of selling to pharmaceutical companies
and turning a profit
Open Issues
• Elodea is the current choice of organism
– Common water weed: robust, packaged for
surviving in water
• The cost of entire project is unknown.
• Legal issues attached to introducing
genetically modified organisms into the
environment?
• Length of effectiveness is unknown
– (How long until the organism reaches max
arsenic uptake capacity?)
• The process of genetically modifying plants is
very slow…
Go/ No Go?
Citations
• Saccharomyces Genome Database
www.yeastgenome.org
• Standard Registry of Biological Parts
www.partregistry.org