Arsenic Used For Breathing

Arsenic is an extremely deadly poison for humans and most of the living beings. As per a new research, it has been discovered that microorganisms are breathing arsenic in a huge area of the Pacific Ocean. According to the team of University of Washington it has been discovered that an ancient survival strategy is still being utilized in the low-oxygen parts of the marine environment.

The researchers are of the view that they were aware for a long period of time that there are extremely low levels of arsenic present in the ocean, but the fact that organisms are using arsenic in order to make a living for themselves -- it's a totally new metabolism for the open ocean. The researchers observed seawater samples from a region below the surface where oxygen is nearly negligible, forcing life to look for alternatives. These regions may undergo expansion in times of climate change. In some of the regions of the ocean there's a sandwich of water where there's no measureable oxygen. The microbes present in these regions utilize other elements that act as an electron acceptor in order to extract energy from food. The most usual alternatives for oxygen are nitrogen or sulfur. As per Saunders' early investigations, arsenic can also be used as an alternative, only that researchers are looking for evidence of the same. The team observed the samples that were collected during a 2012 research cruise to the tropical Pacific, off the coast of Mexico. According to the genetic analyses performed on DNA extracted from the seawater, it was found that two genetic pathways tried to convert arsenic-based molecules as a way to gain energy. The genetic material was targeting basically two different forms of arsenic, and authors believed that the pathways occurred in two organisms that cycle arsenic back and forth between various forms. The results revealed that arsenic-breathing microbes make up for less than 1% of the microbe population in these waters. These microbes discovered in the water are usually distantly related to the arsenic-breathing microbes that are found in hot springs or contaminated sites on the surfaces of land. Biologists are of the belief that the strategy is a holdover from the early history of earth. When life arose on the planet Earth for the first time, the volume of oxygen was extremely low in both the air and in the ocean. Oxygen came up in abundance in Earth's atmosphere only after photosynthesis became a common phenomenon and largely converted carbon dioxide gas into oxygen. Early lifeforms had to utilize energy with the help of other elements, such as arsenic, which was usually more common in the oceans at that point of time.

By: Anuja Arora

Content: https://www.sciencedaily.com/releases/2019/05/190502113603.htm