Bioremediation- The Key to the Future?

Bioremediation broadly refers to the consumption or decomposition of pollutants through both naturally occurring and artificially induced microorganisms. Targeted polluted sites include air, marine ecosystems, soil, flue gasses, etc. 

The microorganisms introduced through bioremediation break down harmful pollutants and chemical compounds into innocuous amounts of harmless gasses and water. The process of bioremediation requires specific environmental factors including temperature, nutrients, and food. To alter such factors amendments can be added through specific techniques under the umbrella term of bioremediation. 

Such techniques include bioaugmentation/biostimulation which enhances pre existing microbial activity through the addition of amendments:organic substrates, electron donors/acceptors, nutrients. Biostimulation is commonly used to alter environmental conditions in order to increase favorability for the growth of certain microorganisms. Meanwhile bioaugmentation may be used to introduce necessary microorganisms which do not naturally occur at a site. However, usage of bioaugmentation comes with a major drawback; it becomes difficult to control the growth of newly introduced microorganisms. Although these methods can be used to artificially enhance bioremediation, intrinsic bioremediation occurs without human help. Intrinsic bioremediation is akin to a nature's own method of cleaning up, occurring most commonly in soil and water.

 In addition bioremediation can be done ex situ, offsite, as opposed to in situ, on site. Ex situ bioremediation is necessary when cleaning up pollutants in unsuitable climates for microorganism growth. Thus when a climate is too frigid or when the water is too acidic ex situ bioremediation is favored. 

A common example of modern bioremediation usage is the cleaning up of oil spills. As most petroleum hydrocarbons present in crude oils also occur naturally in marine ecosystems, oil degrading microorganisms are ubiquitous. Nevertheless, even under aerobic conditions, degradation, especially of less biodegradable compounds such as resin, occurs over extended periods of time. When the 1989 Exxon Valdez oil spill occurred in Alaska, spilling almost 11 million gallons of oil, bioremediation-specifically biostimulation- was used to increase biodegradation rates. The addition of over 100,000 pounds of nitrogen fertilizer into the water provided abundant nutrients and more favorable population growth conditions for oil-degrading microorganisms. 

Bioremediation is one of many examples of biotechnological advances geared towards tackling the ever growing issue of climate change. Despite its drawbacks, bioremediation allows for us to clean up the environment bit by bit.