Biofilm Mediated Degradation of Petroleum Products

The release of petroleum and petroleum derivatives, such as polycyclic aromatic hydrocarbons (PAHs), in the environment owing to anthropogenic activities, has become a major global threat to human health and ecological equilibrium. It causes a number of diseases and petroleum hydrocarbon (PH) compounds bind to soil components, making their removal very difficult. In order to find an eco-friendly, convenient, and non-expensive way, indigenous PH degrading microorganisms are employed. Biofilm, being a syntrophic association plays an important role in PAH degradation. The three-dimensional structure of the biofilm matrix is found to facilitate the efficient and rapid degradation of PAH. Various physicochemical parameters of biofilm are found to regulate the efficacy of PAH degradation. In order to amend certain drawbacks of biofilm mediated remediation, these days microbial electrochemical systems are increasingly being used for redressal of PH contamination, where the solid anode functions as an endless electron acceptor and the microbial activity is stimulated by bio-current in situ to guarantee the PH removal from contaminated soil and water. Following uptake of emulsified PH, it may be denatured by biofilm-associated enzymes or by biosurfactant molecules (such as rhamnolipids). The biomolecules synthesized by the bacterial cells further help in the expression of the specific genes thereby helping in the enhancement of PH degradation.