Synthetic Biology Research: Cyanobacterial Energy Proposal: Polypropylene Biodegrading Bacteria By: Tatiana Gelaf

The Problem  Fossil fuels are limited and cause pollution  1 st generation biofuels: from crops  Use food sources  Environmental impact  Costly  High energy cost (fertilizer)  Highly controversial

Solution using Synbio  Cyanobacteria naturally produce a variety of products which can be used as biofuels.  Hydrogen  Various Alcohols  Synthetic biologists work to make them more efficient in this production.

Hydrogen  Nitrogenase : nitrogen fixation  Hydrogen produced is consumed by hydrogenase.  Synbiologist modifying bacteria to not consume this hydrogen.  Bidirectional hydrogenase: oxidizes/produces  Intolerant to oxygen  Synbiologists working on oxygen-tolerant bacteria.  Fuel source to be burned with only byproduct being water.

Ethanol  Produced through fermentation  Pyruvates  acetaldehyde  ethanol  Engineered to produce more through overexpression of relevant genes.  Used as supplement/replacement to diesel.

Butanol  Two distinct pathways.  Synthetic 2-ketoacid pathway  Uses intermediates from amino acid production  2-ketovalerate  butanol  CoA-dependent pathway  Acetyl-CoA  Butyryl-CoA  Butanol  Occurs in nature.  Production concentrated through introduction of certain enzymes.  Can be used in petroleum engines or mixed with diesel.

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Photanol  Phototrophs+Chemiotrophs  photofermentative systems.  Phototrophs:  use energy from photons  produce C 3  Chemiotrophs  use energy from oxidized compounds in environment  consume C 3  produce various products through fermentation.

Photofermentative system

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Polypropylene Degrading Bacteria

The Problem  Most types of plastics don’t biodegrade.  Remain in environment.  Pose a threat to wildlife.  Release toxins.

Current Technologies  Biodegradable plastics  Crops  Designed to be composted, takes a while  Recycling  Structural problems  Energy expensive  Selected for Bacteria  Produce useless/dangerous byproducts.

Proposed Solution  Polypropylene  propylene  Propylene  Previously produced from fossil fuels  Recycled to polypropylene  Acetone, phenol, isopropanol

Bacteria  Two component signaling: uses polypropylene as chemical signal  Open reading frame codes for one of the following:  Modified endonuclease  hydroxyethylphophonate dioxygenase (HEPD)

Modified Endonuclease  NEase  Covalent intermediate  Modified recognition site  Covalent intermediate: nucleophile  transition metal

HEPD  Cleaves C-C  Uses oxygen + ferric superoxide

Sources biodegradable.html ation.html of-polypropylene-and-modified-polypropylene-structure-effects NU3AJ: 0+&cd=1&hl=en&ct=clnk&gl=us