IGEM:Stanford/2009/Plastic Degradation

Project Summary

Can we convert environmentally hazardous phenols and formaldehyde (the primary components of a class of widely used resins) into a carbon source for E. coli?

Original Presentation: Tough Plastic: Degrading Phenol Resins

Experiment Ideas

Potential subprojects:

1. Phenol Degradation: Goal: Engineer E. coli to metabolize phenol as a carbon source, linking it to cellular respiration To achieve this, we would need to transduce genes (already in the database in PubMed) from some type of fungus or bacteria (such as Pseudomonas aeruginosa AT2, Burkholderia cepacia PW3, or Aspergillus fumigatus ATCC 28282) into E. coli via a plasmid vector. Our choice of genes will depend on whether we decide to introduce enzymes responsible for meta- or ortho- phenol metabolism. The former will result in byproducts that are used in glycolysis; the latter will yield intermediates of the TCA cycle.

2. Formaldehyde Degradation Goal: Engineer E. coli to metabolize formaldehyde as respiration precursor, bypassing the detoxification pathway This would require introducing genes for two enzymes (3-Hexulose-6-Phosphate Synthase and phospho-3-hexuloisomerase) into the E. coli genome through a plasmid vector to introduce the pathway necessary for formaldehyde assimilation. Also, we would have to control the formaldehyde oxidation pathway in E. coli, which detoxifies formaldehyde but does not assimilate it into biomass as a carbon source, either by knocking out or downregulating expression of the genes involved in this pathway.

Questions/Discussion

Is it possible to make phenol and formaldehyde the sole carbon source for E. coli? Would there be any way to compartmentalize phenol or formaldehyde degradation, using previous iGEM work on creating a synthesome? Would there be any crosstalk between the pathways for formaldehyde and phenol degradation that would harm the cells?