NASA researchers have discovereda species of bacteria that, in the absence of phosphorus, is capable of metabolizing arsenic, normally a lethal poison for any organism. Details are published in the magazineScience.
Until now it was thought that the development of life was based on seis essential components: phosphorus, carbon, oxygen, hydrogen, sulfur and nitrogen. However, aGFAJ-1 strain bacteriaof the halomonas family, found in California’s Mono Lake, is able to dispense with the first andgrow in the presence of arsenic, an element that is lethal for most organisms.
From a chemical point of view, arsenic is very similar to phosphorus and that is precisely why it is so harmful to living things, experts from the NASA Astrobiology Institute explained in a statement from Arizona State University. As the metabolism is unable to differentiate both elements in their active biological form, arsenic is assimilated instead of phosphorus and blocks the main biochemical processes. The only known exception is the GFAJ-1 strain, which not only survives in the presence of arsenic, but alsois capable of incorporating the poison into its metabolism and DNA. “This research reminds us that life as we know it can be much more flexible than we normally assume or imagine,” says study co-author Felisa Wolfe-Simon. The finding suggests the existence ofa totally different biochemistry than what we knew until now, which could have been used by microorganismsin extreme environments on Earth or even other planets.
