The discovery of a bacterium that could substitute arsenic for phosphorus to stay alive is refuted by new study. Six elements such as oxygen, carbon, hydrogen, nitrogen, phosphorus and sulphur are considered essential for life. So the announcement in 2010 implied one of biology's golden rules had been broken.One of the papers is authored by Tobias Erb from the Swiss Federal Institute of Technology in Zurich and colleagues and the other comes from a group led by Marshall Reaves of Princeton University in New Jersey.
The new papers suggest instead that though the organism is able to stay alive in high arsenic and low phosphorus conditions, it still needs phosphorus to grow. The most recent studies also found no proof that arsenic was included into the microbe's DNA - as the authors of the original paper had recommended.The researchers argue that the bacterium being highly adapted to the arsenic-rich environment of the lake is thrifty, and has become skilled at scavenging phosphorus under harsh circumstances.