Hydrocarbons are a common contaminant in both terrestrial and aquatic
ecological systems. This is most likely due to the widespread use of hydrocarbons as
everyday energy sources and precursors in the majority of chemical manufacturing
applications. Because of their physical and chemical properties, most hydrocarbons in
the environment are resistant to degradation. Although several derivatives are classified
as xenobiotics, their persistence in the environment has induced microorganisms to
devise ingenious strategies for incorporating their degradation into existing
biochemical pathways. Understanding these mechanisms is critical for microbial
utilization in bioremediation technologies. This chapter focuses on recalcitrant and
persistent hydrocarbons, describing the reasons for their resistance to biodegradation as
well as the effects on ecological systems. Furthermore, aerobic and anaerobic
degradation pathways, as well as ancillary strategies developed by various
microorganisms in the degradation of hydrocarbon pollutants, are discussed.
Keywords: Biodegradation, Fortuitous degradation, Anaerobic degradation, Bioattenuation, Biostimulation, Bioaugmentation, Bioavailability.
