A Greasy Nightmare...
Despite being under your feet and out of sight, sewers are extremely important components of urban infrastructure that help to keep the area safe from flooding and minimize the spread of water-borne disease. Nowadays existing sewer networks are under increasing strain... mainly as a result of population growth, increasing urbanization and climate change. But it’s not just an increased usage of sewers which are beginning to challenge these infrastructural wonders. Human activity can, as per usual, be blamed. Life is like a sewer. You get out what you put into it and, sometimes, it stinks. We have created monsters. We have created fatbergs.
These large congealed masses composed of fat, oil, grease and non-biodegradable materials like wet wipes are beginning to wreck infrastructural havoc, causing thousands of blockages, which the UK government spend millions clearing each year. Though the fatberg issue could be solved by simply changing everyday habits, we - the Warwick iGEM team - have begun to lay the foundations for a biological solution toward this growing problem.
After several brainstorming sessions we came up with a strategy for our mission. After researching more, we found out that fatbergs are made up of several major components like calcium soap, wet wipes and triglycerides. We hypothesised that by breaking down the main component of fatbergs - fat molecules, also known as triglycerides we can break the whole structure to remove the solid mass.
Figure 1 Hydrolysis of a triglyceride molecule into glycerol and three free fatty acid molecules
We were further inspired by the work carried out by the 2014 Sheffield iGEM team, who worked on the fatberg problem. We decided to build upon their foundational research and carry it forward to benefit society by using specific lipases suited to an environment like the sewage system. This includes Thermostable lipase A, as seen below in figure 2 (TliA, an enzyme derived from Pseudomonas fluorescens; a previous iGEM part utilised by Sheffield, as well as the Stuttgart and KAIST iGEM teams.
Figure 2. Three dimensional structure of TliA isolated from Pseudomonas fluorescens as used by the 2014 Sheffield iGEM team.
Infatuation -The Guardians of the Sewers...
Our mission as Warwick iGEM 2019 is to attempt to tackle the growing fatberg crisis. We have implemented two key strategies to do this: preventing their formation through the education of the general public to increase awareness of these monstrous masses, explaining how simple changes in human behaviour can significantly reduce their formation.
Secondly, we will utilise the power of synthetic biology to clone candidate lipases, derived from microorganisms living within fatbergs or sewers, into our E. coli carrier cells. The lipase activity of our clones will then be characterised using both a qualitative and quantitative assay of our own design, alongside experiments to establish the viability of our engineered bacteria in oil.