In Vivo Observation of Cell Division of Anaerobic Hyperthermophiles by Using a High-Intensity Dark-Field Microscope

To study growth and cell division of anaerobic hyperthermophilic archaea in vivo, a cultivation technique using glass capillaries was developed. At temperatures of 90 to 98°C, at least 10 successive cell divisions of Pyrodictium abyssi TAG 11 were documented. Cells divide by binary fission. Visualized under a modified dark-field microscope, the formation of cannulae, which finally connected all cells, was observed. The cannulae elongated at 1.0 to 1.5 μm/min and reached final lengths of between 30 and 150 μm. A “snapping division”-like mode of cell fission was discovered for Thermoproteus tenax.