Bacterial Bio-Resources for Remediation of Hexachlorocyclohexane

Abstract

In the last few decades, highly toxic organic compounds like the organochlorine pesticide (OP) hexachlorocyclohexane (HCH) have been released into the environment. All HCH isomers are acutely toxic to mammals. Although nowadays its use is restricted or completely banned in most countries, it continues posing serious environmental and health concerns. Since HCH toxicity is well known, it is imperative to develop methods to remove it from the environment. Bioremediation technologies, which use microorganisms and/or plants to degrade toxic contaminants, have become the focus of interest. Microorganisms play a significant role in the transformation and degradation of xenobiotic compounds. Many Gram-negative bacteria have been reported to have metabolic abilities to attack HCH. For instance, several Sphingomonas strains have been reported to degrade the pesticide. On the other hand, among Gram-positive microorganisms, actinobacteria have a great potential for biodegradation of organic and inorganic toxic compounds. This review compiles and updates the information available on bacterial removal of HCH, particularly by Streptomyces strains, a prolific genus of actinobacteria. A brief account on the persistence and deleterious effects of these pollutant chemical is also given.

Versatility of Streptomyces sp. M7 to bioremediate soils co-contaminated with Cr(VI) and lindane

“…Actinobacteria represent an important component of the microbial population in soils. They have demonstrated bioremediation ability (Benimeli et al, 2008;Polti et al, 2009;Albarracín et al, 2010;Alvarez et al, 2012). In particular, Streptomyces sp.…”

Evaluating degradation of hexachlorcyclohexane (HCH) isomers within a contaminated aquifer using compound-specific stable carbon isotope analysis (CSIA)

“…Since biodegradation can cause a sustainable and efficient decrease in pollutant mass, it is an important natural attenuation process and needs to be taken into account for MNA strategies (Bombach et al, 2010;Illman and Alvarez, 2009;Wiedemeier et al, 1999). Biodegradation is a sustainable removal process of HCHs in the subsurface (Bhatt et al, 2009) and a cost efficient alternative to physico-chemical remediation of HCH contaminated groundwater and soils (Alvarez et al, 2012;Langenhoff et al, 2013;Phillips et al, 2006). The molecular structure of the HCH isomers plays a key role in biodegradation as it has been shown that a and g isomers are degraded faster than b and d isomers (Lal et al, 2010;Mehboob et al, 2013).…”

Degradation study of lindane by novel strains Kocuria sp. DAB-1Y and Staphylococcus sp. DAB-1W

“…The fatty acid profile identifies the microbial species. A variety of microorganisms degrade the HCH isomers and their degradation studied by many researchers (reviewed by Alvarez et al 2012). …”