Cyanobacterial construction of hot spring siliceous stromatolites in Yellowstone National Park

Living stromatolites in Yellowstone National Park's hot springs, composed of silica-encrusted cyanobacterial mats, exhibit distinct microbial community structures based on water level exposure. Submerged mats are dominated by a novel cyanobacterial phylotype not classified within known subphylum groups, while exposed mats harbor heterocystous phylotypes (Chlorogloeopsis HTF and Fischerella). Molecular analysis revealed that these heterocystous types likely emerge during low water levels, possibly due to environmental pressures like sulfide exposure or oxygen tension. The finely laminated texture of these stromatolites may better resemble ancient forms than coarsely laminated marine examples, offering insights into early Earth microbial ecosystems.

Pepe‐Ranney, C., Berelson, W. M., Corsetti, F. A., Treants, M., & Spear, J. R. (2012). Cyanobacterial construction of hot spring siliceous stromatolites in Yellowstone National Park. Environmental Microbiology, 14(5), 1182–1197. Portico. https://doi.org/10.1111/j.1462-2920.2012.02698.x