A clearer account ...

... Arsenic-loving bacteria may help in hunt for alien life.

The researchers began to grow the bacteria in a laboratory on a diet of increasing levels of arsenic, finding to their surprise that the microbes eventually fully took up the element, even incorporating it into the phosphate groups that cling to the bacteria's DNA.

Notably, the research found that the bacteria thrived best in a phosphorus environment.

That probably means that the bacteria, while a striking first for science, are not a sign of a "second genesis" of life on Earth, adapted specifically to work best with arsenic in place of phosphorus.