In the human world, there is a common misconception that bacteria are “bad.” They are known as the sneaky little creatures that can make your stomach hurt, head hot, and throat painful. However, bacteria are not all that “bad.” Sure, there are pathogenic (disease-causing) bacteria, but there are also many “friendly” and “neutral” bacteria, such as the ones that live in your gut or on your skin.
Humans also tend to overlook how amazingly well-adapted bacteria are to their environments. For example, consider hydrothermal vent bacteria that are able to withstand high pressures, no sunlight, and bitter cold waters in the twilight zone of the ocean. One of the adaptations that allows these microbes to survive in this infernal realm is their unique nutritional mode.
Hydrothermal vent bacteria are chemoautotrophs. This means that the energy and carbon sources they use to sustain themselves are very different from that of terrestrial organisms. Plants use light as the energy source that drives photosynthesis, a process that converts light energy harvested from the sun to chemical energy in the form of sugar. On the other hand, hydrothermal vent bacteria derive the chemical energy required for their metabolism from the inorganic compounds flowing out of hydrothermal vents.
Thanks to their eccentric nutritional mode, bacteria living in the twilight zone are not reliant on the sun as an energy source. Without these microbes, the deep-sea ecosystem would collapse because other organisms depend them as food source. Hydrothermal vent bacteria may be miniscule creatures, but we should not underestimate their extraordinary capacity to adapt to extreme environments and the key role they play in their ecosystem.
Smithsonian Ocean Team. “The Microbes That Keep Hydrothermal Vents Pumping.” Ocean Find Your Blue, Mar. 2016, https://ocean.si.edu/ecosystems/deep-sea/microbes-keep-hydrothermal-vents-pumping
Urry, L. A., M. L. Cain, S. A. Wasserman, P. V. Minorsky, and J. B. Reece. 2017. Diverse nutritional and metabolic adaptations have evolved in prokaryotes. In Urry et al., Campbell Biology 11th edition, 840-867. Pearson Education, Inc., San Francisco, California, USA.
Woods Hole Oceanographic Institution. Hydrothermal Vents. Woods Hole Oceanographic Institution, https://ocean.si.edu/ecosystems/deep-sea/microbes-keep-hydrothermal-vents-pumping