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 and hydroxyl groups.

By conversion to 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 major goal of OSCAR was to be able to remediate toxic components in oil sand tailings ponds, tuning them into useable hydrocarbons. We targeted carboxylic acid remediation, such as naphthenic acids, as they are some of the most toxic components of the ponds. We had a couple approaches to this, with some promising results!

Catechol Degradation

Another toxin we wanted to target was catechol, as it is the common breakdown product of many different toxic compounds. Through modifications to existing registry parts, we showed that we could degrade catechol into 2HMS and then further degrade it into hydrocarbons.

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 desulfurization and denitrogenation. We targeted pathways in a variety of organisms and submitted biobricks for each.