Microbes and petroleum bioremediation

Abstract

Petroleum pollution is an environmental issue often reported, including oil spills that occur accidentally worldwide. The release of large quantities of oil causes directly or indirectly huge environmental and economic impacts and may persist for decades. Bioremediation processes, such as biostimulation and bioaugmentation, among others, represent an eco-friendly and effective way to treat impacted areas based on the use of biological agents, associated or not to other compounds like biosurfactants in order to mineralize or complex organic and inorganic pollutant compounds. Therefore, this book chapter will review some topics related to bioremediation, including several in situ and ex situ techniques employed to treat polluted areas and the use of biosurfactants produced by several microorganisms. Moreover, oil spills and how they can affect marine and terrestrial environments are also mentioned, based on recent reports available in literature and according to organizations responsible for environmental impact monitoring. Hydrocarbonoclastic microorganisms have been described in both environments as well as the community dynamics of specific groups as a function of oil compounds input. In marine environments, a high abundance increase of a specific group called “obligate hydrocarbonoclastic bacteria (OHCB)" has been reported after an event involving petroleum contamination. Similar observation has been reported for mangroves, showing that oil or its derivatives allow the selection of microorganisms capable to degrade hydrocarbons. Petroleum contamination in cold environments, as Arctic and Antarctic regions, represents a huge challenge since management of contaminated sites and bioremediation effectiveness in these regions depend on several factors influencing oil degradation under cold conditions facing intrinsic limiting factors. In conclusion, bioremediation is not only a scientific concept described in literature but a concrete and applied efficient tool to treat polluted environments. The increasing number of bioremediation companies and patents also corroborates the tendency in search for new technologies and approaches focusing on sustainable management of polluted areas.