Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4551107 | Marine Environmental Research | 2011 | 12 Pages |
The present study aimed at characterizing the heavy metal resistance and assessing the resistance pattern to multiple heavy metals (300 mmol L−1) by Palk Bay sediment bacteria. From 46 isolates, 24 isolates showed resistance to more than eight heavy metals. Among the 24 isolates S8-06 (Bacillus arsenicus), S8-10 (Bacillus pumilus), S8-14 (B. arsenicus), S6-01 (Bacillus indicus), S6-04 (Bacillus clausii), SS-06 (Planococcus maritimus) and SS-08 (Staphylococcus pasteuri) exhibited high resistance against arsenic, mercury, cobalt, cadmium, lead and selenium. Plasmid curing confirmed that the heavy metal resistance in S8-10 is chromosomal borne. Upon treatment with the heavy metals, the strain S8-10 showed many morphological and physiological changes as shown by SEM, FTIR and AAS analysis. S8-10 removed 47% of cadmium and 96% of lead from the growth medium. The study suggests that sediment bacteria can be biological indicators of heavy metal contamination.
► Forty six isolates were screened for heavy metal resistance and 24 isolates showed resistance to more than eight heavy metals. ► Among the 24 isolates S8-06 (Bacillus arsenicus), S8-10 (Bacillus pumilus), S8-14 (B. arsenicus), S6-01 (Bacillus indiucs), S6-04 (Bacillus clausii), SS-06 (Planococcus maritimus) and SS-08 (Staphylococcus pasteuri) exhibited high resistance to elevated concentration of arsenic, mercury, cobalt, cadmium, lead and selenium. ► Among the seven strains the heavy metal resistance in S8-10 is chromosomal borne rather than by plasmids. ► Characterization by SEM, FTIR and AAS revealed the morphological changes, variation in macromolecules secretion and accumulation of heavy metals in S8-10 cells. S8-10 removed 47% of cadmium and 96% of lead from growth medium that had initial metal concentrations of 200 ppm. ► The present study is an indicator of the heavy metal pollution in the Palk Bay region and alarms the necessity to monitor the heavy metal load in this region.