Image a creature that could break down environmental toxin, cleaning our water better than we ever have done before. A research team at Princeton reported their discovery of exactly that – a bacteria that provides a more efficient method for treating toxins found in swage, fertilizer runoff, and other forms of water pollution on April 11, 2018 in PLOS ONE journal. The bacteria, Acidimicrobiaceae bacterium A6, can break down ammonium anaerobically, or without oxygen. This is a hug breakthrough as an alternative method to the costly oxygen-dependent methods currently used in sewage treatment.
Waste water treatment plants benefit heavily from this discovery, as many of them discharge into watersheds and must remove ammonium beforehand. Doing so has always requires churning copious amounts of oxygen into the waste to feed the bacteria that carries out the process. Most bacterium use oxygen in a chemical reaction that turns ammonium into nitrite, which is then converted into benign nitrogen gas by another type of bacteria.
Before conducting their experiment, the authors of the study hypothesized that A6 performs the Feammox reaction instead, a chemical reaction that breaks down ammonium, taking place in wetland environments such as the riparian wetlands and New Jersey. Scientist previously were unsure of what enabled this reaction to occur, but after conducting a study in 2015, they found that the Feammox reaction only took place in swamp samples where Actinobacteria were present.
In the study most recently published by the researchers at Princeton, mixtures of soil samples and metal mediums were placed in an oxygen-free environment to mimic wetland soil where the bacteria originated. After checking samples every two weeks over a year, the scientists discovered a sample of soil where ammonium degradation took place. They identified that A6 was the bacteria carrying out the Feammox reaction through genetic sequencing.
Researchers emphasized the potential to treat other environmental pollutants found in oxygen-poor areas, such as underground aquifers. A6’s ability to remove environmental toxins from waste opens up the doors for ensuring clean water in a variety of situations, from sewage treatment to cleaning up contaminated wells.
The research team hopes to explore how to build a reactor where the A6 bacteria can be used on an industrial scale to process ammonium. In fact, they are in the works of building a prototype reactor with the Chinese environmental ministry. Besides oxidizing ammonium, A6 can also remove two common pollutants that are hard to treat called trichloroethylene and tetrachloroethylene.
This discovery has the potential to address a range of environmental problems as ammonium has dire effects on the environment if not removed for water sources. Once in waterways, ammonium can cause of a depletion of oxygen as well as eutrophication, an excessive growth of algae. Both have detrimental effects to watershed ecosystems, from streams to rivers to oceans. Taking advantage of bacteria A6 could save not only ecosystems and environmental health, but protect human health as well.
Shan Huang, Peter R. Jaff�. Isolation and characterization of an ammonium-oxidizing iron reducer: Acidimicrobiaceae sp. A6. PLOS ONE, 2018; 13 (4): e0194007 DOI: 10.1371/journal.pone.0194007