Microbial approaches to oil spill remediation

Abstract

Microbial Bioremediation (BRM) is an effective technique for removal of hydrocarbons (HCs) using sustainable methods from contaminated ecosystems. The microbial enzymes from bacteria, fungi, and yeasts convert the toxic HCs into non-toxic by-products that include carbon dioxide, water, and microbial biomass. Typically, the enzymes oxygenases, peroxidases, and laccases obtained from microorganisms namely Pseudomonas, Alcanivorax, Bacillus, Aspergillus, and Phanerochaete chrysosporium help in the breakdown of the hydrocarbons. The BRM efficiency is affected by numerous parameters such as temperature, microbial community makeup, oxygen availability, and hydrostatic pressure. As an example, the low temperature and hydrostatic pressure supresses microbial processes whereas aerobic conditions increase enzyme activity. The build-up of oxygenated polyaromatic hydrocarbons may hinder decomposition and present environmental hazards. Currently bioaugmentation techniques and consortia of microbes have been suggested to improve degradation efficiency, observed in deep-sea and marine environments. Two innovative techniques that have advanced our understanding of microbial interactions and dynamics are the "Oil-spill snorkel" and meta-omics. The consortia of Fungal-bacterial strains of Indian origin are typical examples of regional adaptation promising an efficient and targeted clean-up of complex hydrocarbon contaminants using BRM.