PARIS (AFP) - Scientists on Sunday said they had gained insights into a remarkable bacterium that lives without oxygen and transforms ammonium, the ingredient of urine, into hydrazine, a rocket fuel. So-called anammox germs caused a sensation when they were first identified in the 1990s, but uncovering their secrets is taking time. In a letter published by the UK science journal Nature, researchers at Radboud University Nijmegen in the Netherlands reported they had identified the molecular mechanism by which the bugs do their fuel-trick. "Proving this was quite a feat," said Prof Mike Jetten from the university's Institute for Water and Wetland Research.