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]

• Some applications of bacterial glue (from news)

Fiber-Hungry Bacteria Could Form Natural "Bond" With Wood Industry (Jul 2004)

Bacterial Glue Could Become Medical Adhesive (Apr 2006)

Water Decontamination Application Example (Smart Filtration System)

• Forrest:
  • 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 (can be put back into the river or otherwise used, etc)
  • 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)

• Bernice:
  • Bacteria lights up when on filter material (perhaps at a certain concentration)
  • When filter glows to a certain extent, we know it's time to change the filter
  • Forrest: could we just add dye to the bacteria to stain it a certain color?

Toxic Metals: Arsenic, Beryllium, Cadmium, Hexavalent Chronium, Lead, Mercury

Toxic Metal Exposure

Organic pollutants: Benzene, toluene, xylene, formaldehyde

Persistent organic pollutants (POPs)

Charles River remediation efforts

Group eyes lawsuit over Charles River pollution

Organic Compounds in the Charles River

Creating a Hypothetical Martian Ecosystem

• Using photosynthetic bacteria to make oxygen on Mars

• Fungus eats radiation for breakfast

• Syntrophus aciditrophicus (extreme bacteria) has had its genome sequenced

• Geobacter bacterium has environmental restorative capabilities

Photoreceptor Bacteria

• E. Coli that derive their energy from light
• Media:liphardt.pdf