Biotransformation of Heavy Crude Oil and Biodegradation of Oil Pollution by Arid Zone Bacterial Strains

Abstract

The present century has seen tremendous progress in various types of renewable fuels and its possible applications. Fossil fuel, such as crude oil remained as prime source of energy, and it still fuels industries and households. In fact the demand for fossil fuels has increased in the last decade or so, because of increased population and demand due to industrial revolutions. It also leads to increased incidences of crude oil-related pollutions, oil spills, pipeline damages, accidental or intentional spillage, release from tankers, etc., which are quite persistent and very difficult to remediate. Heavy crude oil spillage is even more difficult to remediate, due to its hydrophobic, toxic constituents, and its partial or incomplete degradation leads to even more toxic intermediates in the affected environment. Harmful effects of crude oil spills are often observed in marine mammals, birds, and land-based animals, including humans. Commonly used remediation practices are often not quite effective and lead to only partial removal. Microbial biodegradation is reported to be an effective and environment-friendly alternative, which could be applied under both aerobic and anaerobic conditions onshore or offshore. Bacteria from marine and arid region are reported to be better biodegrader as compared to fungi. Several types of enzymes are reported to be quite effective for catalytic conversion of heavy crude oil and its derivative constituents. Recent progress in genetic engineering and omics techniques will be quite useful for further identifying the metab-olomic routes and devising an efficient biodegradation to completely harmless end products.