Team:VIT Vellore

togglepH - iGEM Competition 2018

togglepH

About our project

An increase in industrialization has led to an overall increase in the carbon footprint, the major component being CO2 which in turn led to global warming. Among other ill effects of industrialization, the one that has garnered a lot of attention is what we call Ocean Acidification. It is also known as "the other CO2 problem" and that's where our engineered microbe jumps in.

Geology reports suggest that between the years 1751 to 1996 there has been an increase of H+ ions of upto 30%. Apart from that, the overall pH has been decreased from 8.25 to 8.14. Increasing acidity is directly linked to having potentially harmful consequences for marine organisms, such as depressing metabolic rates and immune responses in some organisms, and causing the worst cases of coral bleaching.

"If we continue emitting CO2 at the same rate, by 2100 ocean acidity will increase by about 150 percent, a rate that has not been experienced for at least 400,000 years."- United Kingdom Ocean Acidification Research Programme, 2015

Our engineered vibrio will interact with its surrounding environment to give real-time H+ data which is then used by pH-sensitive NhaA and CadA promoters which give maximum expression at pH 8.5 and pH 7 respectfully; after which the expression is down-regulated. Within this 1.5 pH window, our biobricks are designed such that the carbonic anhydrase genes bring about a reduction in ocean acidification. Once the pH is stabilized, repressor proteins are expressed which block the carbonic anhydrase expression so that no more shuttling of H+ takes place thereby saving marine flora and fauna from any more damage.