Team:Groningen/Application

From 2009.igem.org

Modular System

The metal scavenger with a vertical gas drive is a modular system which contains five modules; the transporter, an accumulation protein, a regulated promoter, a regulator and the gas vesicle cluster. The transporter imports the metal ion of choice. An accumulation protein facilitates accumulation of metal ions and prevents the cell from dying of the metal toxicity. The imported metal ion also acts as a regulator for the metal sensitive promotor which activates the expression of the gvp-cluster. Thereby the recombinant bacterium, with this system, accumulates metal and upon accumulation starts to float which is convenient in bioremediation or mining

Application

Water Cleaning

Bacteria which accumulate metal ions can be used to remove toxic metals or other contaminants from ground or surface water. This microbial [system] is described for scavenging of arsenate, copper and zinc. An example where removal of arsenic from subsoil water by this organism could prevent serious poisoning of millions of people. In Bangladesh and other countries over ten million water pumps where installed, to improve personal hygiene but this raised a new problem. An unforeseen consequence was that because the groundwater level dropped dramatically the arsenic contamination in the groundwater, delivered by the Ganges and the Brahmaputra, began oxidizing. This poisoned water may be absorbed by the bacteria and after filtering the bacteria out it can be used by individuals.

Sludge Cleaning

ur first goal is to create a bacterium that is able to absorb and encapsulate metals and that floats. In this way one would be able to separate the metals and the sediment. Simply put the bacteria and the sediment in large container stir them together and let the cleaned sediment sink and scoop of the floating metal filled bacteria. Such a purification plant would look similar like the sewage disposal plants that we use today. Simply inject the bacteria in the sediment, let the bacteria that are full of metals float to the surface and collect them further downstream with the help floaters which are now used to contain oil pollution in the sea.

Mining

Ethical concerns

One of the most prominant ethical issues surrounding the application of genetic modified organisms is safety.The application should not be an environmental hazard by itself nor should it be a hazard for human health. Using a confined disposal plant would for most part prevent the spread of genetically modified bacteria into the environment, however, in case of heavy rain the basins can overspill which allows the bacteria to enter the environment. So only a confined basin is not enough, a self-destruction plasmid, which induces cell death after a certain time, should be added as well. In that case, even if the bacteria accidently end up outside the confined disposal plant, they will die after a while and will be unable to spread or transfer their DNA. This death plasmid should be carefully choosen since the bacteria need time to clean the water, sludge or mine the metals. Read more on safety and ethical issues...