Fifteen years ago, a group of scientists made a bold claim in Science, one of the world’s most prominent research journals: They had discovered a microorganism that could survive using chemistry different from any known life-form.

On Thursday, the top editors of Science formally retracted the 2010 paper, saying it was fundamentally flawed. The journal’s editors did not accuse the paper’s authors of misconduct or fraud. Instead they said they were motivated to conclude a chapter of scientific debate that had roiled research institutions and the lives of academics who once were brought under intense scrutiny by social media and bloggers.

The paper’s authors disagree with the decision to retract the paper. Their defenders, including science officials at NASA, which helped fund the original research, say the move is outside the norms of what usually leads to the striking down of a published paper.

“The change in policy at the journal, Science, to retract research publications due to a disconnection between the data and the published conclusions is unprecedented and upends the current standards in the research and scientific fields,” said Nicky Fox, the associate administrator of the science mission directorate at the space agency.

Dr. Fox added that the agency encouraged the journal “to reconsider its retraction.”

In 2009, researchers collected a microbe from Mono Lake, a salty and alkaline body of water in California. In the lab, they said, they found it could replace phosphorus, a key chemical for all known biological beings, with arsenic, an element that is typically toxic. If the discovery were confirmed, it would change scientists’ fundamental conceptions about life on Earth, and in the cosmos. They named the microbe GFAJ-1.

The finding traveled beyond the terrain of academic conferences and scientific journals, amplified by teasers from NASA and the journal. Following a livestreamed NASA news conference, the discovery picked up the hashtag #arseniclife on Twitter, then a nascent social media platform, which other scientists used to express serious concerns with the study’s methodology and conclusions. Eventually, a general scientific consensus emerged against the claim that the microbe incorporates arsenic into its basic functioning.