A single strain of a budding bacterium was isolated from freshwater. The strain had a life-cycle, with a multitrichous swarmer stage, and produced a phase-dark inclusion of packed ribosomes and nuclear material. The mol % G + C of the DNA was 64.4 +/- 1.0. A new genus, Gemmata with the type species Gemmata obscuriglobus is proposed. The type strain is UQM 2246.