Chemical substances may be combined or converted to others by means of chemical reactions. Forms of energy, such as light and heat, are not matter, and are thus not substances in this regard.
Halophiles are organisms that thrive in high salt concentrations. They are a type of extremophile organism. The name comes from the Greek word for salt-loving. While most halophiles are classified into the Archaea domain, there are also bacterial halophiles and some eukaryota, such as the alga Dunaliella salina or fungus Wallemia ichthyophaga. Some well-known species give off a red color from carotenoid compounds, notably bacteriorhodopsin.
There are three major known groups of Archaebacteria: methanogens, halophiles, and thermophiles. The methanogens are anaerobic bacteria that produce methane. They are found in sewage treatment plants, bogs, and the intestinal tracts of ruminants.Ancient methanogens are the source of natural gas. Halophiles are bacteria that thrive in high salt concentrations such as those found in salt lakes or pools of sea water.Thermophiles are the heat-loving bacteria found near hydrothermal vents and hot springs.ncient methanogens are the source of natural gas. Halophiles are bacteria that thrive in high salt concentrations such as those found in salt lakes or pools of sea water. Thermophiles are the heat-loving bacteria found near hydrothermal vents and hot springs.