Chemosynthesis

Large populations of animals can be supported by chemosynthetic secondary production at hydrothermal vents, methane clathrates, cold seeps, whale falls, and isolated cave water.

Giant tube worms use bacteria in their trophosome to fix carbon dioxide (using hydrogen sulfide as their energy source) and produce sugars and amino acids.

In 1897, Wilhelm Pfeffer coined the term "chemosynthesis" for the energy production by oxidation of inorganic substances, in association with autotrophic carbon dioxide assimilation—what would be named today as chemolithoautotrophy.

At about the same time, then-graduate student Colleen Cavanaugh proposed chemosynthetic bacteria that oxidize sulfides or elemental sulfur as a mechanism by which tube worms could survive near hydrothermal vents.

[9][10] In 2013, researchers reported their discovery of bacteria living in the rock of the oceanic crust below the thick layers of sediment, and apart from the hydrothermal vents that form along the edges of the tectonic plates.

Preliminary findings are that these bacteria subsist on the hydrogen produced by chemical reduction of olivine by seawater circulating in the small veins that permeate the basalt that comprises oceanic crust.

Chemosynthetic communities in different environments are important biological systems in terms of their ecology, evolution and biogeography, as well as their potential as indicators of the availability of permanent hydrocarbon- based energy sources.