Oxygen's key role as a reactant during aerobic hydrocarbon degradation led to the belief for many years that n-alkanes and other hydrocarbons were recalcitrant under anoxic conditions. Research during the last 15 years, however, has shown that microorganisms have adapted and evolved to use hydrocarbon substrates under varying reducing conditions and that they employ novel biochemical processes to activate these compounds in the absence of oxygen.
The central role of oxygen as a reactant in aerobic hydrocarbon breakdown led many to believe for a long time that n-alkanes and other hydrocarbons were unreactive under anoxic conditions. However, recent research has shown that microorganisms have developed ways to use hydrocarbon substrates under various reducing conditions and employ novel biochemical pathways to activate these compounds without oxygen.