Sensitivity of Four Cyanobacterial Isolates from Tropical Freshwaters to Environmentally Realistic Concentrations of Cr(6+), Cd(2+) and Zn(2.).
Sensitivity of four tropical cyanobacteria viz. Coelosphaerium sp., Synechococcus sp., Oscillatoria sp. and Chroococcus sp. to environmentally relevant concentrations of Cr(6+), Cd(2+) and Zn(2+)was assessed based on fluorescence change as a proxy for growth reduction. At 24 h exposure, the growth reduction inthe cyanobacteria followed the order: Zn(2+) < Cr(6+) ≤ Cd(2+). Of the four cyanobacteria, Synechococcus was the most sensitive for Cr(6+), where as Chroococcus was the most sensitive for Cd(2+)and Zn(2+). Sensitivity was gradually decreased by 96 h implying the acquisition of tolerance by cyanobacteria to heavy metal ions with prolonged exposure.
Department of Microbiology, Faculty of Science, University of Kelaniya, Kelaniya, GQ, 11600, Sri Lanka.
Thilini
T
Munagamage
Department of Microbiology, Faculty of Science, University of Kelaniya, Kelaniya, GQ, 11600, Sri Lanka. vayanga@kln.ac.lk.
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Rathnayake
Department of Zoology and Environmental Management, Faculty of Science, University of Kelaniya, Kelaniya, GQ, 11600, Sri Lanka.
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A
Pathiratne
Faculty of Science and Information Technology, Global Centre for Environmental Remediation (GCER), The University of Newcastle, University Drive, ATC Building, Callaghan, NSW, 2308, Australia.
Mallavarapu
M
Megharaj
D002104:Cadmium / Q000032:analysis / Q000633:toxicity*; D002857:Chromium / Q000032:analysis / Q000633:toxicity*; D000458:Cyanobacteria / Q000187:drug effects* / Q000378:metabolism; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D054300:Oscillatoria / Q000187:drug effects / Q000378:metabolism; D046940:Synechococcus / Q000187:drug effects / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*; D015032:Zinc / Q000032:analysis / Q000633:toxicity*
D014874:Water Pollutants, Chemical; D002104:Cadmium; D002857:Chromium; C074702:chromium hexavalent ion; D015032:Zinc
Cadmium; Chromium; Concentration response; Cyanobacteria; Fluorescence; Zinc