Scientists baffled by discovery of bacteria that ought to be too big to function

Thin strands of Thiomargarita magnifica bacteria cells next to a U.S. dime. “Given their size, I never imagined them to be single-celled bacteria.” However, years of follow-up studies involving microscopic imaging and DNA sequencing convinced Gros and his collaborators that the filaments were a member of the Thiomargarita genus of bacteria. “For the first time ever, I got to play with bacteria with a pair of tweezers,” said Volland, a marine biologist at the Lawrence Berkeley National Laboratory and lead author of the paper in Science. “This makes T. magnifica a fascinating example of a bacterium that has evolved a higher level of complexity,” Volland said. “I routinely remind people that bacteria aren’t primitive — they’ve evolved just as much as we have,” Eisen said.