Bioremediation of Industrial Waste Using Microbial Metabolic Diversity

Introduction

Our environment is severely contaminated by fast industrialization and by the application of organic chemicals/pollutants in various sectors throughout the world. Plastic, dyes, chlorinated aliphatic hydrocarbons and aromatic hydrocarbons are important groups of these pollutants. Since the start of the industrial revolution, these compounds entered the environment in excess due to leakage, improper disposal or accidents. Ulrich et al. (2009) reported that more than one third of the 1.4 million gasoline storage tanks in US are leaking aromatic hydrocarbons and the amount of chlorinated aliphatic hydrocarbons which reached surface water in the Netherland was about 11000 ton in 2001.These compounds form a long-lasting danger in the environment to human health and ecosystem functioning because of their toxic and carcinogenic effects, persistence and bioaccumulation. The U.S. environmental Protection Agency (EPA) has enlisted 129 compounds causing potential hazard in the environment and kept them in the category of priority pollutants. The list mainly contains chlorinated aliphatic and aromatic compounds.

Microbial biomass plays an important role in the soil ecosystem where they fulfil a crucial role in nutrient recycling and decomposition. Microorganisms have evolved an extensive range of enzymes, pathways and control mechanisms in order to degrade and utilize pollutants as an energy source (Talaro and Talaro, 2002). All the organic compounds in existence are thought to be thermodynamically unstable to varying degrees, and in principle can be mineralised by microorganisms to generate CO₂ and energy for their own growth.A successful bioremediation technique requires efficient bacterial strains to degrade largest pollutant to a minimum level in shortest time. Knowledge of bacterial interactions with soil environment is advantageous to expedite the process in minimum time.