Team:NDC-HighRiverAB/Human Practices

Project Description

What is a Fatberg?

After hearing on the news about giant "fatbergs" that have clogged sewer systems around the world, our team - Notre Dame Collegiate (NDC), decided to try to tackle the problem. A fatberg is a clump of non-biodegradable solid matter such as wet wipes with solidified grease or cooking fats holding it together. Local waste water treatment facilities experience issues with fats that cause inefficiency and extra steps in the treatment system, as they must mechanically break apart the fats which often end up coming back together.

Project Overview

Our team is working on getting our E. coli to express the EstA gene. The EstA gene codes for an esterase (an enzyme) that breaks bonds found in common fats so that the fats will breakdown. Our current promoter is BBa_R0011 that will be turned on by the addition of IPTG, but will hopefully one day be turned on by triglycerides in a sample.

To test that our bacteria is working correctly, we plan to use a compound called esterified 4-nitrophenol that has the bond in fats that we are looking to break. When the bond is broken in this compound, it will turn green; the more green colour in our sample (bacteria and esterified 4-nitrophenol), the more bonds have been broken by our esterase. We are also exploring a few more ideas such as adding our bacteria to an agar plate with triglycerides (fats) on it, and measuring the acidity of the sample (as one of the products of fat breakdown, fatty acids, will decrease the pH).

We have a few options when it comes to delivering our bacteria into the system; one is to introduce it to the rich E. coli population that is already a part of the treatment process. The second will use their current method of vacuuming the fat layer off the wastewater, but instead of them mechanically breaking apart the fats and putting them back into the wastewater, they would put them into a separate container where we would add our bacteria. The benefit to the second option is that our bacteria are contained, and we can use the products for other things; A past iGEM team (MIT 2015) was investigating taking fatty acids and turning them into biofuel which would be a great way to use the products of our fat breakdown.

Image of a Fatberg
Credit:
https://www.rt.com/uk/408737-fatberg-london-sewer-battle/