Abstract

The unprecedented population increase and industrial development during the twentieth century has increased conventional solid and liquid waste pollutants to critical levels as well as produced a range of previously unknown strange synthetic chemicals for which society was unprepared. Increasing pollution of the environment by xenobiotic compounds has provoked the need for understanding the impact of toxic compounds   on microbial populations, the catabolic degradation pathway of xenobiotics and upgrade in bioremediation processes. Adaptation of native microbial community to xenobiotic substrates is thus   crucial for any mineralization to occur in polluted environment. Enzymes which catalyze the biodegradation of xenobiotics   are often produced by induction process and this subsequently determine the acclimation time to xenobiotic substrates. Microbial degraders are adapted to xenobiotic substrates via various genetic mechanisms that subsequently determine the evolution of functional degradative pathways. The ultimate goal of these genetic mechanisms is to creating novel genetic combinations in microorganisms that facilitates mineralization of xenobiotics. Moreover, recent development of high-throughput molecular techniques such as polymerase chain reaction (PCR), microarrays and metagenomic libraries have helped to uncover issues of genetic diversity among environmentally relevant microorganisms as well as identification of new functional genes which would enhance pollution abatement management in the twenty-first century.

Key words: Biodegradation, bioremediation, DNA, metagenomics, microarrays and xenobiotics.