Team:BGU-Israel/Description
Project Inspiration
Have you ever wondered what is happening inside the sewer system? If you look it up, you will discover a world-wide "smelly" problem, with tremendous economic and ecological consequences. The estimated annual cost caused by wet wipes' damages in sewer systems in Israel only, is over 3.5 million dollars. In Israel alone we use about 3.5 billion wipes every year! That is in average of 407 wipes per person. This year, our IGEM BGU-Israel team has decided to take an act and try to tackle this problem using synthetic biology methods.
After a massive research, which included – studying the different wet wipes products and the wet wipes market size, understanding the chemical structure of wipes, collecting sewer blockages data from the ministry of Environmental Protection in Israel and several wastewater treatment facilities – we were ready to continue and design our project step by step.
Why did we focus on wipes? Wipes are being used in many aspects of our life, having different and varied purposes: cleaning wipes, cosmetic wipes, medical wipes, baby wipes and more. At the end of the day, many people flush them down in the toilet instead of throwing away to the trash can, and that is where the big problem begins.
Meet the fatbergs! fatbergs are created from wipes that were tied and tangled together inside the sewer system. First, the wipes absorb high amount of water next, they accumulate and conglomerate along with oils and grease. Eventually a huge fatberg is created and clogs the pipes. We see more and more news reports around the world about "bus-sized" fatbergs, causing wide-scale damages to the sewer system and the sewage treatment processes, which in turn may cause great environmental damages when the sewage leaks into the environment and aquifers upon clogging.
Today there is still no proper solution to this problem. Our IGEM team, BGU-Israel WIPEOUT, intends to help solve this problem using two main approaches both of which are preventative measures:
- Preventing the creation of fatbergs inside the sewer system using Syn Bio tools.
- Raising public awareness to prevent tossing wet wipes to the toilet.
We suggest using genetically engineered bacteria, that present cellulolytic digestive complex on its surface through an AIDA-1 auto-display system and a delivery system in order to degrade down the chemical bonds of cellulose fibers of wet wipes being synthetic or natural.
To achieve our goal, we designed our system according to important information that we have collected:
- Examination of the sewer bacterial population for the selection of model organisms - we reviewed several scientific articles regarding sewer microbiome characterization and we decided to select E.coli as the model organism - both because it exists in the sewer and because it is convenient for laboratory work as a model bacteria with multiple available tools to manipulate it.
- Characterization of the environmental conditions in the sewer and how the sewer system is built - we understood that the sewer system is a dynamic system characterized by a variety of parameters: variable flow intensity (peak hours), acidity, aerobic and anaerobic conditions, presence of oils, fats and detergents, etc..
- Location of treatment centers and characterization of the materials we would like to treat - We talked to several experts in the field to understand what solution we can offer, who our "customers" will be (individuals, sewage treatment plants etc.) and where to place our solution along the sewer system.
- Construction of the enzymatic complex - understanding that cellulose does not cross the bacterial membrane requires an external complex that is displayed on the cell surface. We learned about a multi-enzyme-cellulose-breakdown complex that exists in nature (Cellulosome) and we thought of ways to construct a complex containing the minimal number of enzymes as possible.
- Learning from the efforts of previous "IGEM" teams - we read what previous teams have done and how their efforts can be continued. We found the 2016 British Columbia team and decided to include in our project one of the endo-glucanases they tested, the one that showed the best results - Endo5a.
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Finding a delivery system - Transformation of the complex to other bacteria in the sewer - We tried to think of a method for "sewer engineering", meaning that with a 'one-time intervention' in the system of introducing our engineered bacteria, we can create a continuous transition of the cellulose decomposition system to other bacteria in the sewer. Therefore, we researched the topic of ICE - Integrative and Conjugative Elements.
By finding a solution to this problem we may be able to prevent both ecological and economic problems originating from flushing of wet wipes down the toilet. In the future this could be applied in more fields in the sewage and waste pollution.
Together, we can Wipe out wet wipes from the environment!