ABSTRACT
The organochlorine hexachlorocyclohexane (HCH) is a broad-spectrum insecticide that was used worldwide. Hexachlorocyclohexane is acutely toxic to mammals due to its mutagenic, teratogenic, and carcinogenic properties. Its high persistence ensures HCH residues are found all over the world. Eco-friendly techniques using different microbial species have become the focus of interest for cleaning up contaminated environments. The current trend is the utilization of native microorganisms from polluted sites. Many Gram-negative bacteria have been reported to have metabolic properties to degrade HCHs. Such is the case of several Sphingomonas strains isolated from polluted soils, which were capable of degrading HCH isomers. Meanwhile, among Gram-positive microorganisms, actinobacteria have received great global interest for several biotechnological applications, including bioremediation. In fact, many actinobacteria strains have a great potential for HCHs removal. In this chapter, it is intended to compile and update the information available on the bacterial aerobic degradation of HCHs. Besides, information about the sources and harmful effects of organochlorine pesticides is also given.
