Phototroph is an organism that can use visible light as a primary energy source for metabolism, a process known as photosynthesis. Phototrophs contrast with chemotrophs, which obtain energy from the oxidation of organic compounds. Most phototrophs are autotrophs, also known as photoautotrophs, making use of the energy obtained from photosynthesis to assimilate carbon dioxide (CO2). Photoheterotrophs produce ATP using solar energy, but their source of carbon for biosynthesis is reduced organic compounds. From an ecological point of view, it has been considered that life on Earth is dependent on photoautotrophy, although the recent discovery of submarine strict chemolithoautotrophs is challenging this concept. Phototrophic organisms contain pigments that allow the use of light as an energy source.
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© 2011 Springer-Verlag Berlin Heidelberg
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Peretó, J. (2011). Phototroph. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-11274-4_1206
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-642-11271-3
Online ISBN: 978-3-642-11274-4