EXPLORATION OF ARSENIC AND CADMIUM TOLERANT BACTERIAL GENE POOL FROM INDUSTRIAL AND MINING AFFECTED AREA OF CHHATTISGARH
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Date
2018
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Indira Gandhi Krishi Vishwavidyalaya, Raipur
Abstract
Heavy metal contamination has become one of the most dangerous threats to the environment and human health. In the present study, 108 Arsenic (As) tolerant bacteria and 58 Cadmium (Cd) tolerant bacteria were isolated from soil and water from industrial and mining affected area of Chhattisgarh, India. Further, A total of 27 potential isolates were further screened for their ability to tolerant highest level of As. Whereas 15 efficient isolates were further screened to select best Cd tolerant isolates. The bacterial isolates RpSWA2 and RnASA11 were able to tolerant at 600 mM As(V) and at 30 mM As (III). All selected As and Cd resistant bacteria isolates were characterized morphologically and biochemically. In antibiotic susceptibility test, the maximum bacterial isolates were showed resistance against to ampiciline and rifamycin antibiotic.
The genomic DNA of all As and Cd tolerant bacterial isolates were amplified with 16S rRNA gene specific universal primer yielding a 996bp DNA amplicons. On the basis of 16S rRNA gene sequence, As tolerant bacterial isolates were identified to varying genera as Bacillus, Enterobacter, Klebsiella, Pantoea, Acinetobacter, Cronobacter, Pseudomonas, Agrobacterium and Cedecea. While Cd tolerant bacterial isolates were identified to varying genera as Enterobacter, Serratia, Klebsiella, Pantoea, and Pseudomonas. Further, arsB gene was successfully amplified from genomic DNA of As tolerant bacterial isolates BGWA1, BSSA1, RgCWA1, RpUWA1, RpSWA2, RpSWA4 and RnASA11, with yielding a 750bp DNA amplicons and arsC gene from isolates BGWA1, BHSA6, RpUSA10, RpSWA2 and RnASA11, with yielding an approx 350 bp DNA amplicons. However, isolates BGWA1, RpSWA2 and RnASA11 have showing the presence of both arsB and arsC genes with sets of primer. Sequencing and Blastx homology (for conserved domains protein sequence) confirm amplified product belong to the same gene i.e. arsB (arsenical efflux pump membrane protein ArsB) and arsC (arsenate reductase (glutaredoxin) enzyme). While czcA gene was successfully amplified in genomic DNA of Cd tolerant bacterial isolates BMSA1, RgCWC3 and RgCWC4.
Further, in bioremediation assay raveled that the As bacterial isolates RpSWA2 and RnASA11 were showed significant reduction of arsenate i.e. 33.1%, and 44.1%, respectively as compared to control. However, a mixture of both isolates was showed maximum reduction of arsenate (57.6%). Similarly, isolates RpSWA2 and RnASA11 were showed significant reduction of arsenite i.e. 35.6% and 38.8% respectively as compared to control whereas a mixture of both isolates was showed maximum reduction of arsenite (48.8%). Cd tolerant bacterial isolates BSWC3 and RpSWC3 were showed significant reduction of cadmium i.e. 44.46% and 40%, respectively. A mixture both isolates BSWC3 and RpSWC3 showed maximum reduction of cadmium (50.92%). These bacterial isolates can be exploited for bioremediation of arsenic and cadmium contaminated sites.
Description
EXPLORATION OF ARSENIC AND CADMIUM TOLERANT BACTERIAL GENE POOL FROM INDUSTRIAL AND MINING AFFECTED AREA OF CHHATTISGARH
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