In neutral pH wetland sediments, the pathway by which methane (CH4) is produced by anaerobic microorganisms from decaying plant material is well known. Interestingly, the organisms that make methane (methanogens) cannot use the plant material directly and are dependent on other microbial groups to convert them into simple the simple molecules they use. Thus, a complex interacting "food chain" of microorganisms is needed to convert organic matter to methane and changes in the activity of any group in that chain can affect the entire process. We presently have little understanding of these activities and the organisms involved in acidic bogs.

Plant material consists mainly of large insoluble polymers like cellulose, lignin, and proteins that microorganisms cannot take up into their cells. Hydrolytic enzymes are produced by fermentative microorganisms to cleave off smaller molecules that such as sugars and amino acids that dissolve in water. These then can be utilized by the fermentative organisms that convert them mainly to hydrogen and carbon dioxide (H2/CO2) and fatty acids such as acetic acid, the main component of vinegar, as well as to longer fatty acids. These longer-chain acids are then converted to acetic acid and H2/CO2 by a group of organisms called syntrophs. The net result of these two groups is to convert the plant organic matter to H2/CO2 and to acetic acid that can then be used by the methanogens.

The CO2-reducing methanogens produce about one third of the methane by the equation:

4H2 + CO2 à CH4 + 2 H2O

The acetotrophic methanogens produce about two-thirds of the methane by the equation:

CH3COOH à CH4 + CO2

The net result of all these reactions is that the plant material is converted to nearly equal amounts of CH4 and CO2, sometimes called marsh gas or biogas, which can be seen bubbling up out to the sediments. In 1776, Allessandro Volta showed that marsh gas collected in an inverted funnel was flammable, and even made a cork-shooting pistol using marsh gas/air mixtures.

While it is likely that conversion of plant material to methane in acidic bogs follows the same pattern as in neutral pH sediments, there are contradictory results, and multiple failures to culture the responsible organisms. One of our goals is to improve our understanding of these organisms by culturing them.