Bioremediation at Work: Using Bacteria to Rebalance the Mercury Cycle

Photo by p.Gordon |

Since the dawn of the industrial revolution some 200 years ago, our planet has been witness to a significant increase in the presence of a largely unwelcomed guest: mercury.

Moreover, this mostly-foe has further tampered its reputation in recent years through studies revealing its alarmingly toxic effects, as well as the ease with which human contamination may occur through the process of bioaccumulation, in which the toxin is not only conserved as it moves up the food chain, but accrues itself, resulting in more potent toxic abilities.

Although previous initiatives have reduced industrial mercury pollution in developed nations, the currently accepted strategies reveal serious shortcomings, such as markedly increased emissions in underdeveloped nations. A recent advancement made by scientists at the Inter-America University of Puerto Rico, however, promises to change all that with a bold vision for the future.

Through the insertion of two particular genes into the E. Coli genome, the enzyme polyphosphate kinase and the protein metallothionein are able to bind to the heavy metal and prevent its toxicity in living cells. Surprisingly, the study revealed that this bioengineering marvel may effectively allow the cells to not only tolerate the mercury safely, but absorb up to 24 times more than the maximum mercury level for an unmodified cell. In doing so, the modified bacteria effectively absorbed up to 80% of the mercury to which they were exposed.

At first glance, the study appears to provide a viable strategy in reducing mercury exposure in both animals and humans, but further analysis reveals further innovative, wide-scoping implications. This is because it not only allows for mercury to be essentially ‘stock-piled’ in a systematic manner, but this mercury basin may then be recycled through the use of cytochemistry to provide mercury for more useful, if often overlooked, purposes. Through mass-scale implementation, researchers hope that they will be able to have greater control of the mercury cycle, allowing humans to offset mercury concentrations through positive/ negative feedback loops and thereby minimize toxic exposure through food and water.

Although large-scale implementation involves further research and logistics, scientists are more than hopeful for the future, confident that elevated levels of ambient mercury have far overextended their stay in our one and only beloved home.