Crude Oil Pollution

Since the industrial revolution, crude oil has been the major source of energy which powers daily life. Crude oil otherwise known as fossil fuel, consists of a complex mixture of different molecular weight hydrocarbons and organic compounds that are explore from the earth. Crude oil is heterogeneous in nature with the main constituents being aromatic and aliphatic hydrocarbons, asphaltines and resins (Al-Gamdi, 2011). At high temperature and pressure, crude oil is formed through the pyrolysis of the hydrocarbons through different types of reactions most of which are exothermic reaction (Arun et al. 2011). Distillation of crude oil results in the production of different types of fuel which elutes at different boiling points such as petrol, kerosene,

Pollution caused by crude oil and its petrochemical based products disrupt and alter the ecosystem balance. Incomplete combustion of crude oil leads to the production of greenhouse gases which causes acid rain and also accelerates climate change which is already having negative effect on the environment. Crude oil pollution poses a huge risk to the ecosystem if not properly managed because it enters the food web through the plant which is later transferred from one food chain to the other food chain (Sathishkumar et al. 2008). The strong persistence nature of crude oil and its total petroleum hydrocarbon (TPH) derivatives in air, water and land has attracted much attention from government and environmental stakeholder because accumulation of this pollution in plants and animal tissues leads to toxic, carcinogenic and mutagenic effects which invariably leads to death (Abd-Elsalam et al. 2009; Liu et al. 2010; Das and Chandran,

Aerobic catabolism is the first initial step in microbial degradation of PAH which involves incorporation of two atom of oxygen into the aromatic nucleus of the PAH in an enzymatic reaction catalysed by peroxidases, monoxygenase and oxygenase (Das and Chandran, 2010). The incorporation of oxygen into the structure of PAH is the rate limiting step. Oxidation reaction by dioxygenase enzymes incorporates two atoms of oxygen into PAH ring structure. Initial oxidative reaction by dioxygenase enzyme leads to the formation of cis-dihydrodiol (Bamforth and Singleton, 2005; Das and Chandran, 2010). Cis-dihydrodiol undergoes dehydrogenation reaction to form catechols. Catechols further undergoes ortho and Meta cleavage which results in the formation of acid and aldehyde. Ortho cleavage uses catechol-1,2-dioxygenase to produce cis,cis-muconic acid while meta cleavage uses catechol-2,3-dioxygenase to produce 2-hydroxymuconic