GFAJ-1 Arsenic-Eating Bacteria Discovered; Life on Other Planets Probable?

During last week most of the websites said that NASA was about to reveal something incredibly interesting, which is related to the alien-life forms. There must have been many people who believed that NASA might say that they made contact with an alien life form, or something similar.

The news finally arrived, and NASA did not made contact with an alien life-form, but they made a discovery which might make us rethink about our life here on Earth and about the possible life on other planets. They have discovered a new element which might be related to life. In case you did not know, life on Earth exists thanks to six different elements: oxygen, hydrogen, carbon, nitrogen, sulfur and phosphorus. Without one of them we would not be able to live, and life here on our planet would end. The scientists have stated that they have found a bacterium which is able to live by consuming arsenic instead of phosphorus. The discovery might not seem important, but it could prove that life on other planets might be possible. This means that somewhere out there life might exist, as those life forms might use different elements in order to live.

In most of the cases, the scientists have stated that life can not exist on a planet because it does not have the elements required for sustaining life. The truth is that life could have existed out there and that the life forms from the other planets could have not needed the same elements as we do in order to survive. The arsenic is a toxic element, and the scientists have said that the discovery made us realize that there are many things about life that we still might not know, that we only make certain assumptions about. The news made big splash, and NASA even received phone calls from the White House, which asked about the importance of the discovery. Felisa Wolfe-Simon, a NASA astrobiology member at the United States Geological Survey in Menlo Park, California, is the one who made the discovery; as she scrapped the bacterium from Mono Lake in California. She kept it in a laboratory and she “fed” it arsenic, slowly increasing the dosage of arsenic and decreasing the dosage of phosphorus. The scientists have stated that if the discovery would prove to be true, then the notion of life will be greatly expanded.

They would have to reconsider certain planets as possible homes of life forms, and to even try and send probes there in order to collect samples. Dimitar Sasselov, who is an astronomer at the Harvard-Smithsonian Center for Astrophysics, said that in most of the cases the nature chooses only certain molecules in order to sustain life, even if there are thousands of them. He said that the discovery might prove that nature is not so picky, and that it might be using other chemicals and molecules as well. Dr. Wolfe-Simon said that the discovery is really amazing and important, as it proves to us that life can be sustained in different manners, and not just in the manners we are familiar with. She stated that the discovery is not about the new element which can sustain life, but about acknowledging and accepting the fact that we do not know everything we thought we knew, and that there might be life out there somewhere as well. Caleb Scharf, who is an astrobiologist at Columbia University, said that the discovery really impressed him, because it proved that the life forms have an incredible desire to survive. He said that the bacterium which Felisa discovered remained alive because it consumed something which it would not consume under normal circumstances.

Dr. Wolfe-Simon and her colleagues collected the bacterium from the bottom of Mono Lake, which is known to be highly alkaline and hypersaline. On top of that, the lake is known for the fact that it has the highest concentration of arsenic in the world. The bacterium is called GFAJ-1, and it has been grown in the laboratories by Dr. Wolfe-Simon and her colleagues. There were some people who believed for a very long time now, that there might be certain life forms which might be able to survive with other elements. One of these people is Professor Paul Davies, who is a cosmologist at Arizona State University, and who has been involved in the research as well. He said that the new bacterium is incredible, as it has the capacity of using both phosphorus and arsenic as well. He said that because of that, it can not be really considered an alien life form, as the elements which it uses can be found here on Earth. He believes that there might be other similar organisms out there, which might be able to live under very harsh conditions, using other elements in order to survive. He said that the real discovery would be an organism which does not contain phosphorus at all, because it would prove that life forms could adapt everywhere.

It is believed that these results will have a huge importance when it comes to the Mars expeditions and to the expeditions on other planets as well. All the expeditions on these planets were conducted in order to find out if they contain the elements required for life, but they did not took in consideration the possibility that life might exist even when those elements that sustain life here on earth are not present there. There were numerous such projects, and all of them had the task of finding the life sources which exist here on this planet. Dr. Wolfe-Simon believes that because of those beliefs, we might have missed precious information. She said that those expeditions, especially the ones that took place in the 70s, were conducted before the discovery of many of the strange life forms from the bottom of the oceans, and from the very harsh regions of Antarctica. Dr. Sasselov said that if NASA will conduct future such expeditions, they should really consider looking for other possible elements which might be able to sustain life, not only for the ones which sustain life here on Earth.

As I said, there are six elements which all the life forms from our planet need in order to be able to live, and so far we were not able to find any substitutes for these elements. The scientists believe that this discovery might change things, as now they might look for possible other elements which might have the possibility of replacing these six. When she made the discovery, Dr. Wolfe-Simone was surprised by the fact that life can be so amazing and do things which are much unexpected. She said that she is convinced of the fact that life might have another ace up her sleeves, and that we might be surprised by the possible future discoveries. The scientists have stated for a long time that the best thing for them would be to replace the carbon with the silicon. The majority of them have stated that his might be accomplished somewhere in the future, and that the discovery really got them excited about the future possible discoveries.

Arsenic is somewhat very similar to the phosphorus, as it is located right besides it in the periodic table of elements. It has many of its characteristics, but despite of the resemblances, the arsenic is toxic whereas the phosphorus is not. Dr. Wolfe-Simon said during a conference from 2006, that there might be certain bacteria which have started using arsenic instead of phosphorus, and which are no longer affected by it. She said that everything was related to the process of evolution, and that if a life form is accustomed to certain changes, then those changes might become a part of it, over numerous generations. She said four years ago that arsenic might be used in order to sustain life, but her theories were not considered to be too important back then. Mary Voytek, who is the senior scientist for NASA’s program in astrobiology, said that the discovery is very different from all the other discoveries, because it proves that there might be certain life forms which have the arsenic built into their system. Because of that, she believes that life might exist on the other planets as well. There were some who said that the discovery was not that great, and the reason for that is the fact that the bacterium was found in waters which contained very high levels of arsenic. They said that the discovery did not prove that life might exist through other elements, but simply that the life form can evolve in order to survive in harsh conditions, which was already known. Dr. Wolfe-Simone said that even if she believed that these organisms exist, she wasn’t certain of their existence, and that she was happy that her predictions proved to be true.

She said that she was surprised by the fact that there were certain bacteria which survived in the lake, which was kind of odd, giving the level of arsenic it contained. She also mentioned that there was a clear difference between the usual bacteria which live on phosphorus and the ones who live on arsenic, as the ones who can survive the toxic element are larger than the regular ones. They have reached to the conclusion that the arsenic has replaced some of the elements from the bacteria, and that the bacteria now rely on the arsenic instead of the other elements. However, the researchers have realized that the bacteria preferred phosphorus, as it grew better and survived for a longer period of time in it, than in the arsenic. Dr. Wolfe-Simone said that the bacteria still contained phosphorus, even after it only received arsenic as a main diet. Davies also mentioned that this is the first time when a life form which can survive through a different element besides the known six ones. He is convinced that the discovery will lead to the creation of a new field in biology.

Steven Benner, who is a member of the Foundation for Applied Molecular Evolution in Gainesville said that the discovery is not valid, as the bacteria would not be able to survive on arsenic alone. He said that it is not possible from a chemical point of view, because as soon as the phosphorus would be removed from the bacteria, a chemical reaction would cause the destruction of the bacteria. Benner said that the only way in which bacteria might be able to survive without the phosphorus would be if it would have suffered a genetic mutation, and he believes that it did not happen. It is unknown where this discovery will lead to, but the entire world is waiting for the outcome.