Team:METU Turkey project

Degredo PETronum!

ABSTRACT

The usage of polyethylene terephthalate-PET (as like plastic bottles or textiles) is one of the big problems of our era. Many plastic bottles are not reusable and are not safe for hot liquids or for use in dishwashers or microwaves. Some tougher, reusable plastic bottles may cause cancer. The main disadvantage of plastic bottles is that so many of them end up in landfills instead of being recycled. It takes thousands of years for plastic bottles to biodegrade, and the degrading process emits toxic chemicals into the air. We may alter the destiny of plastic in useful way.

OUR MISSION

Our project aims to clean enviroment with the degredation of PET to pyruvate by E.coli. With this project,while the environment will be cleaned from PET, the E.coli would add pyruvate to the cell cycle and use it as a new source. We divide our project into two parts. At the first part we found gene design for converting the PET into 2-hydroxymuconate semialdehyde in iGEM database. The arrangement at the bottom explains the first part:

At the second part, we wanted to go further and researched the gene parts for convertion of 2-hydroxymuconate semialdehyde into pyruvate. This part will give us the chance of adding new parts to iGEM database. In this arrangement, it can be observed in detail:

Why do we want to degrade PET? As you know, plastic smears into the soil and water easily, although plastic producing companies claim that, they collect the plastic lower quality available again and this way allows recycling , it is possible to see PET in water and soil. Our aim is to separate freshwater(rivers and lakes), salt water(sea and oceans) and the most important, the soil from this carcinogen with biodegradation method which we design with E.coli. Despite of recycling of PET, after a while it would be a substance which is unusable and unrecyclable and because of this reason we want to design an organism to degrade it.

How the PET smears to the lakes? Ultimately, people live close to water resources, at the same time betray water. Plastic smears water at different forms( like bottle,bag or pot) and the damage increases with uncollected years. Derraik, J.B, (September 2010). The pollution of the marine environment by plastic debris: a review. Marine Pollution Bulletin, 44(9), 842-852. Retrieved from http://www.sciencedirect.com/science/article/pii/S0025326X02002205

How does our project work?

Totally degradation of PET to pyruvate is done by E. coli.

As an analog: The project depends on E. coli that eats PET as we eat sandwiches.

The Circuit of our Project

The Circuit of our Kill Switch Model

We made a design for collected plastic and aim to having a bacteria pool of plastic which our organism degredate PET without producing toxic material. In this design, controlled biodegradation is very important because we can not precise all the risks. So, we made our organism addicted, briefly it works with a kill-switch mechanism with the presence of arabinose.

Who will our project help?

Our project will help the environment to become cleaner.

Why did we choose this project?

The biodegradation of plastic bottles took thousands of years, and the degrading process emits toxic chemicals into the air. Our project aims to clean enviroment with the degredation of PET to pyruvate by E.coli. With this project,while the environment will be cleaned from PET, the E.coli would add pyruvate to the cell cycle and use it as a new source.

Can our bacteria degrade PET in huge amounts?

For nowadays, yes. Also we can do this biodegradation process with different organisms like algeas in water. For soil, situation is more complicated but actually, we try to obtain this biodegradation genes from a soil organism Pseudomonas putita. E.coli can be worked as easy as P. putida and has a good adaptiton. If we talk about a biodegradation on a collected plastic, our project would work properly.

Why did we associated some of our parts with Pseudomonas putida F1 strain?

P. putida is used for related experiments and it has lots of metabolic similarities with E.coli

Could we use P. putida F1?

Unfortunately, it is easy to handle but obtaining a gene is very tough. The errors in the experiments show us there is a problem in the primers. Because of limited budget and time, we could not obtain F1 gene, but constructed our project in E. coli DH5a.