Understanding the Behaviour of Oil-Degrading Micro-Organisms to Enhance the Microbial Remediation of Spilled Petroleum

Petroleum-contamination of both terrestrial and marine environments have persisted as a result of the increasing demand on liquid petroleum globally which has led to the need to clean up spilled petroleum using eco-friendly methods. Of all the petroleum-cleaning techniques explored, the use of petroleum-degrading microbes has received most attention. The microbial remediation of spilled petroleum has been proved to be cost-effective, eco-friendly and sustainable. However, these microbes have been found to thrive under certain environmental/nutritional conditions which influence their behaviour towards spilled petroleum. This study aims to identify the factors responsible for the change in behaviour of oil-degrading microbes which might help facilitate better petroleum spill management. Some of these factors include: the physical nature of the spilled petroleum; chemical nature of the spilled petroleum; availability of nutrients; water temperature; concentration of oxygen; soil region/soil particle size; competition from other micro-organisms. Petroleum-degrading microbes were also found to degrade specific hydrocarbon components in liquid petroleum due to the specific metabolic pathway utilized by individual microbes. This makes the use of a microbial consortium a more aggressive option for the microbial degradation of spilled petroleum than the use of microbial isolates. However, more research on the factors influencing theabundance and productivity of oil-degrading anaerobes may need to be carried out. Also, how oil-degrading microbes can be aided to break down asphalthenes should be investigated.