IGEM:MIT/2007/Updated Ideas

Estrogen Biosensor

• some articles:
  • Bacterial biosensor of endocrine modulators [1]
  • A yeast sensor of ligand binding [2]
  • Biosensor for estrogen in water samples [3]

sticky project:

input:

• temperature (cold shock / heat shock promoters)
• light (either via light sensitive transcription/translation or photo-induced chemistry)
• cell growth (stationary phase, log phase)
• cell type (if growing different strains)
• metal ion (metal sensitive promoter)
• estrogen (ER binding domain)
• cre/lox recombination

parts:

• mussel peptide fused to circularly permuted OmpX (surface display protein, see Rice07)
  • need tyrosine hydroxylase to convert tyrosine to L-DOPA (hydroxylation)? can also occur non-enzymatically (reversible)
  • need tyrosinase to convert L-DOPA to DOPA-quinone (oxidation)? can also occur non-enzymatically (reversible) -- heavy metal ions (like copper) can catalyze...
• polystyrene peptide fused to OmpX

output:

• stick to specific surface (plastic, polystyrene, etc)
• stick nonspecifically (noncovalently) to surface (mussel peptide in reduced DOPA form)
• crosslink and stick (covalently) to surface and each other (mussel peptide in oxidized quinone form)

output apps:

• microbial biofilms/membranes
• bacterial photo-lithography (light-induced glueing)
• population separations
• sensor readout
• "Enhanced Bioaccumulation of Heavy Metal Ions by Bacterial Cells Due to Surface Display of Short Metal Binding Peptides"[4] Check out refs about bacteria that "bioprecipitate" heavy metal ions

articles on heavy metal adhesion:

• [5]

Water Decontamination Application Example

• Water is collected from a river (or other source) into a filtration setup
• Bacteria is added to the water
• The bacteria bind to or take in metals or other pollutants (input 1: detection/uptake of pollutant)
• Input causes bacteria to be able to bind to the filter material (output 1: stickiness to filter material)
• The water is now pollutant-free
• The filter can be cleaned by rinsing/soaking it with water while shining light on it (input 2: light)
• This second input causes the bacteria to unbind from the filter material (output 2: loss of stickiness to filter material)