11/05/2025
Scientists have discovered Candidatus Thiomargarita magnifica, a bacterium large enough to be seen with the naked eye, living on decaying mangrove leaves in Guadeloupe. Measuring up to two centimeters in length, this single-celled organism challenges long-held assumptions about bacterial simplicity and size limitations. Unlike typical bacteria, it contains thousands of membrane-bound compartments known as pepins, each housing DNA and ribosomes, enabling localized genetic activity and protein synthesis. Its genome, nearly 12 million base pairs long and replicated hundreds of thousands of times, represents an unprecedented level of polyploidy. This complex internal organization blurs the boundary between prokaryotes and eukaryotes, revealing that bacteria can evolve architectural and functional sophistication once thought exclusive to higher life forms. The discovery expands our understanding of microbial diversity and redefines the structural limits of single-celled life.
Scientists describe Candidatus Thiomargarita magnifica, a centimeter-long bacterium with membrane-bound DNA and ribosome-containing organelles, challenging ideas about cell size and complexity.
