Sensitivity of Four Cyanobacterial Isolates from Tropical Freshwaters to Environmentally Realistic Concentrations of Cr(6+), Cd(2+) and Zn(2.)

• Published in: Bulletin of environmental contamination and toxicology Vol. 96; no. 6; p. 816
• Main Authors: Munagamage, Thilini, Rathnayake, I V N, Pathiratne, A, Megharaj, Mallavarapu
• Format: Journal Article
• Language: English
• Published: United States 01-06-2016
• Subjects: Cadmium - analysis; Cadmium - toxicity; Chromium - analysis; Chromium - toxicity; Cyanobacteria - drug effects; Cyanobacteria - metabolism; Fresh Water - chemistry; Fresh Water - microbiology; Oscillatoria - drug effects; Oscillatoria - metabolism; Synechococcus - drug effects; Synechococcus - metabolism; Water Pollutants, Chemical - analysis; Water Pollutants, Chemical - toxicity; Zinc - analysis; Zinc - toxicity; Chromium; Fluorescence; Cadmium; Zinc; Cyanobacteria; Concentration response
• ISSN: 1432-0800
• DOI: 10.1007/s00128-016-1809-4

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.