OSCAR

The Optimized System for Carboxylic Acid Remediation, or OSCAR, is the Destroy component to our iGEM 2012 Calgary project. Building on last year's biosensor, OSCAR converts toxic compounds, such as naphthenic acids and catechol, into hydrocarbons by removing unwanted carboxylic acid functional groups from their intricate chemical structures. By creating hydrocarbons we can not only detoxify tailing waters but provide an economically viable method for doing so. By using flux balance analysis we developed a system to optimize the output of carboxylic acid removal system which we validated in the wetlab. Furthermore we developed a bioreactor prototype to demonstrate the applicability of our system using novel hydrocarbon collection methodologies. Finally, we developed constructs and genetic circuits to upgrade these hydrocarbons to reduce sulfur and nitrogen content. Altogether, OSCAR provides a method to upgrade naphthenic acids and other toxic components from waste products into useable fuels.

What is OSCAR composed of?

Decarboxylation

The first part of any biosensor is to be able to detect that a compound is present. This traditionally relies on promoters that are responsive to a certain compound. We have created a transposon library that will determine genetic elements that will activate in the presence of toxins. We used naphthenic acids as the initial screening compound due to the difficulty in detecting them and their role as one of the most hazardous toxins in the tailings ponds.

Catechol Degradation

After being able to detect the compounds we need FRED to be able to tell us about them. With the challenges provided by the tailings ponds we decided to improve upon last year's single output electrochemical system to create a triple output system. This novel approach to electrochemical reporting has provided us with a fast and accurate measurement approach that can function in environments where fluorescence or luminescence would fail.

Flux Analysis

Once we had our bacteria producing hydrocarbons out of tailings pond toxins, we wanted to figure out how to optimize their efficiency. We developed a program to optimize the metabolic network of our synthetic organism using a mathematical model which predicts compounds that could be fed to the organism to increase hydrocarbon production. Once complete, we validated it in the wetlab, and developed a graphical user interface using the matlab platform, allowing all iGEM teams to use it in their application.

Bioreactor

With our biological systems showing some promising results in terms of decarboxylation, we needed to think about where OSCAR could live. He needed a house: a bioreactor! We first used Maya to create a model animation, and then designed and prototyped it. We tested its functionality in terms of a few different parameters, trying to find the most efficient design.

Oil Upgrading

Once we knew that we could turn carboxylic acids into hydrocarbons, we wanted to explore how to upgrade them. Sulfur and nitrogen are both compounds abundant in the tailings ponds and that reduce the quality of fuels produced. They also produce toxic compounds when burned, making them undesirable. We explored ways to remove these components through desulphurization and denitrogenation. We targeted pathways in a variety of organisms and submitted biobricks for each.