First, the hog waste is placed in an anaerobic digester, which contains bacteria that consume the manure and release methane gas.

FORBES: Written by John Platt

Methane is the final product of the anaerobic metabolic pathway of clostridium bacteria breaking down organic matter in the absence of oxygen, primarily cellulose.

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Anaerobic microbes--bacteria that live without oxygen--were generating the methane.

FORBES: Magazine Article