a phenomenon known as cometabolism also adds greatly to the variety of copolymers that bacteria are able to synthesize. Cometabolism was first reported in 1960, in studies of methane-oxidizing bacteria. When these bacteria metabolize a growth-supporting hydrocarbon substrate, such as methane, they can also incorporate and oxidize other hydrocarbons, eventhough those hydrocarbons would not be utilized if they were present alone.We will encounter this phenomenon again chapter 14 in the context of environmental degradation of foreign organic compounds.