Metabolic profiles and phylogenetic diversity of microbial communities from chlorinated pesticides contaminated sites of different geographical habitats of India.
OBJECTIVE
To study the microbial communities in three sites contaminated with chlorinated pesticides and evaluation of dehydrodechlorinase (linA) gene variants involved in gamma-hexachlorocyclohexane (γ-HCH, lindane) degradation.


RESULTS
Using a culture-independent method, 16S rRNA genes were amplified from microbial communities occurring in contaminated soils. From 375 clone libraries analysed, 55 different restriction fragment length polymorphism phylotypes were obtained. Dehydrodechlorinase (linA) gene, which initiates the γ-HCH degradation, was directly amplified by PCR from the DNA extracted from soils. Deduced amino acid sequences of eight variant genotypes of linA showed few amino acid changes. All the variants of linA had mutations of F151L and S154T, and one of the genotype carried 12 amino acid changes when compared to a linA of Sphingomonas sp. reported from the same soil.


CONCLUSIONS
The microbial communities displayed complex and diverse groups similar to bacteria involved in biodegradation. The presence of biodegradative genes like linA indicates the presence of communities with capacity to biodegrade the persistent pesticide HCH.


CONCLUSIONS
This study provides insights to evaluate the presence of catabolic genes and assessing the bioremediation potential of the industrial soils contaminated by chlorinated pesticides.
Manickam
N
N
Environmental Biotechnology Division, Indian Institute of Toxicology Research (Council of Scientific and Industrial Research), Mahatma Gandhi Marg, Lucknow, India. manickam65@yahoo.com
Pathak
A
A
Saini
H S
HS
Mayilraj
S
S
Shanker
R
R
D001419:Bacteria / Q000145:classification* / Q000235:genetics / Q000378:metabolism; D001673:Biodegradation, Environmental; D001556:Hexachlorocyclohexane / Q000032:analysis / Q000378:metabolism*; D007194:India; D056186:Metagenomics; D010573:Pesticide Residues / Q000032:analysis; D010575:Pesticides / Q000378:metabolism*; D010802:Phylogeny; D016415:Sequence Alignment; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D020578:Sphingomonas / Q000235:genetics
D010573:Pesticide Residues; D010575:Pesticides; D012987:Soil; D012989:Soil Pollutants; D001556:Hexachlorocyclohexane