Scientists Discover Parasitic Microbe with Smallest Known Genome That Challenges Definition of Life

Scientists discover Candidatus Sukunaarchaeum mirabile, a parasitic microbe with the smallest known genome at just 238,000 base pairs that lacks metabolic genes and survives entirely by hijacking host cells, challenging fundamental definitions of life and revealing up to 50% of bacterial species may be similar hidden parasites.

• Scientists discover Candidatus Sukunaarchaeum mirabile, a parasitic microbe with the smallest known archaeal genome at just 238,000 base pairs that lacks virtually all metabolic genes and cannot process nutrients or grow independently
• The organism retains only its core replication machinery while depending entirely on host cells for survival, challenging fundamental definitions of life that typically require metabolism as a key component
• Researchers estimate that 25-50% of bacterial species may be similar parasitic organisms living within other cells, suggesting a vast hidden world of microbial biodiversity yet to be discovered