ABSTRACT
Microbes that use carbon dioxide as a source of cell carbon must find a source of electrons to reduce the carbon to the level used in organic molecules. There are two basic functions of all living cells. The first is to extract energy from either an energy-yielding chemical reaction or from light energy. The second is to apply that energy to the synthesis of new cell matter. To synthesize a microbial cell, one needs to know what makes up the insides of a cell. Carbon dioxide, carbonic acid, and bicarbonate, and even carbonate if it remains soluble, are available to microbes. The higher plants and the photosynthetic microbes are responsible for the oxygen in Earth’s atmosphere. They are the primary producers, not only of oxygen but of all the organic compounds that make up the Earth’s rich biosphere. Yellowstone is a pretty extreme environment, but these microbes can also be found in more normal circumstances.
