title: Engineering bacteria for bioremediation of persistent organochlorine pesticide lindane (γ-hexachlorocyclohexane).
abstract: Strategies were designed for bioremediation of the highly persistent toxic pesticide γ-hexachlorocyclohexane (γ-HCH) or lindane from the environment. Lindane caused the loss of stress-protective chaperone GroEL, and inhibited photosynthesis, respiration and nitrogen-fixation in Anabaena, resulting in growth arrest. To alleviate lindane toxicity, the linA2 gene, encoding HCH dehydrochlorinase from Sphingomonas paucimobilis B90, was knocked-in at an innocuous locus in Anabaena genome and over-expressed from an eco-friendly light-inducible PpsbA1 promoter. The recombinant Anabaena degraded >98% of 10 ppm lindane within 6-10 days. A LinA2 overexpressing Escherichia coli strain could degrade 10 ppm of all the isomers of lindane within 1h and displayed a visual degradation zone on a newly designed histochemical plate containing 50mg lindane within 12h. The study demonstrates (a) bioremediation of traces of lindane prevalent in paddy fields, using bioengineered photoautotrophic Anabaena, and, (b) biodegradation of huge stockpiles of lindane, by employing recombinant live/dead E. coli.
authors.affiliation: Molecular Biology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085, India; Samsung Biomedical Research Institute, School of Medicine, SKKU, Suwon 440 746, South Korea.
authors.forename: Akhilesh Kumar
authors.initials: AK
authors.lastname: Chaurasia
authors.forename: Tapan Kumar
authors.initials: TK
authors.lastname: Adhya
authors.forename: Shree Kumar
authors.initials: SK
authors.lastname: Apte
mesh_terms: D017033:Anabaena / Q000235:genetics* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000378:metabolism; D001673:Biodegradation, Environmental; D004926:Escherichia coli / Q000378:metabolism; D005798:Genes, Bacterial; D005818:Genetic Engineering; D001556:Hexachlorocyclohexane / Q000378:metabolism*; D010575:Pesticides / Q000378:metabolism*; D011995:Recombination, Genetic / Q000235:genetics; D020578:Sphingomonas; D013312:Stress, Physiological; D015262:Xenobiotics
chemical_list: D001426:Bacterial Proteins; D010575:Pesticides; D015262:Xenobiotics; D001556:Hexachlorocyclohexane
keywords: LinA2 overexpression; Lindane bioremediation; Lindane toxicity and detection; Recombinant E. coli/Anabaena strains