title: Uptake of Pb(2+ )by a cyanobacterium belonging to the genus Synechocystis, isolated from East Kolkata Wetlands.
abstract: East Kolkata Wetlands is a conserved wetland utilizing sewage and garbage, generated by Kolkata Municipal Corporation area for cultivation purpose. Cyanobacteria are the photosynthetic prokaryotes having bioremedial capacity. We have isolated a cyanobacterium from the sewage recycling fish-pond of East Kolkata Wetlands. Partial sequence of 16S rDNA gene of the isolated strain showed 100% similarity with that of genus Synechocystis. Isolated strain and Synechocystis sp. PCC6803 survived up to 300 mug ml(-1) Pb(2+ )and growth was completely inhibited at 400 mug ml(-1) Pb(2+). All experiments were carried out with 100 mug ml(-1) Pb(2+) in which growth was the maximum. 91.67% of the total Pb(2+) got adsorbed to the outer surface of the cell and 1% of the total Pb(2+) entered the cell of the isolated strain as estimated by atomic absorption spectrometry, but in Synechocystis sp. PCC6803 72.72% adsorbed and 0.96% penetrated. Intracellular and periplasmic depositions of Pb(2+) were observed in both the strain. A filamentous structure developed outside the cell wall of the isolated cyanobacterium, but very little change was observed in Synechocystis sp. PCC6803. ZiaR-SmtB like regulator gene was expressed in both the strains after Pb(2+) induction. The cDNA sequence of ZiaR of the isolated cyanobacterium shows 100% homology with that of Synechocystis sp. PCC6803. Upon Pb(2+) induction, expression of SOD gene increased. cDNA sequence of the SOD gene from the isolated strain showed 98% homology with that of Synechocystis sp. PCC6803. Enzymatic activity of catalase and SOD was also increased. No DNA damage was monitored upon induction with Pb(2+).
authors.affiliation: Department of Biophysics Molecular Biology & Genetics, University of Calcutta, University College of Science & Technology, 92 A. P. C Road, Kolkata 700009, India. oxide_5@rediffmail.com
authors.forename: Sanchita
authors.initials: S
authors.lastname: Roy
authors.forename: Amar Nath
authors.initials: AN
authors.lastname: Ghosh
authors.forename: Ashoke Ranjan
authors.initials: AR
authors.lastname: Thakur
mesh_terms: D001483:Base Sequence; D002374:Catalase / Q000378:metabolism; D004249:DNA Damage / Q000235:genetics; D004269:DNA, Bacterial / Q000235:genetics; D007194:India; D007854:Lead / Q000378:metabolism*; D050296:Microbial Viability; D046529:Microscopy, Electron, Transmission; D008969:Molecular Sequence Data; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D046939:Synechocystis / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism* / Q000648:ultrastructure; D053833:Wetlands
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S; D007854:Lead; D002374:Catalase; D013482:Superoxide Dismutase