Hot Vent Microbiology
Hot vent microbiology refers to the microbial diversity associated with underwater hot springs known as hydrothermal vents. Chemical analysis of hydrothermal fluids shows large amounts of reduced inorganic materials, including H2S, Mn2+, H2, NH4, and CO. The system is based on chemolithoautotrophy (nitrifying metal- and sulfur-oxidizing microorganisms and methanogens). Hydrothermal vents combine several extreme conditions including temperature (up to 380 °C), pressure (20 MPa at 2,000 m), and pH (plumes of pH 2.5), in the absence of sunlight, all of which determine that primary producers have to use chemical energy for CO2fixation. The temperature gradient from the surrounding water that is heated up to 300–400 °C by magma that pours out through cracks in the lithosphere to seawater, which remains around 2 °C, creates a very unstable environment. Chimney growth from mineral precipitation when hydrothermal fluids come into contact...