Environmental constraints defining the distribution, composition, and evolution of chlorophototrophs in thermal features of Yellowstone National Park

A combination of temperature, pH, and sulfide levels significantly influences the distribution, diversity, and evolution of chlorophototrophs—microorganisms that use chlorophyll to convert light into chemical energy—in Yellowstone National Park's thermal features. Research revealed that genes involved in chlorophyll biosynthesis are constrained to temperatures below ~70°C and thrive best under circumneutral to alkaline pH conditions. Acidic pH, often linked to sulfide oxidation, reduces bicarbonate availability, limiting chlorophototroph survival. Spring pH was the strongest predictor of phylogenetic diversity among these organisms, with chlorophyll a and bacteriochlorophyll a predominating, suggesting a dominance of Cyanobacteria and Chloroflexiales. The study analyzed geothermal gradients across Yellowstone, correlating environmental factors with genetic and pigment data to uncover these constraints.

HAMILTON, T. L., VOGL, K., BRYANT, D. A., BOYD, E. S., & PETERS, J. W. (2011). Environmental constraints defining the distribution, composition, and evolution of chlorophototrophs in thermal features of Yellowstone National Park. Geobiology, 10(3), 236–249. Portico. https://doi.org/10.1111/j.1472-4669.2011.00296.x