https://ogma.newcastle.edu.au/vital/access/ /manager/Index en-au 5 https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:43986 Wed 05 Oct 2022 14:36:29 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:38869 Mesotaenium sp., Chlorococcum sp. and Scenedesmus sp.) to environmentally relevant concentrations of hexavalent chromium (Cr⁶⁺) and cadmium (Cd²⁺) was compared individually in three growth media viz. Bold's Basal Medium (BBM), Test Medium 1 (TM1) and Test Medium 2 (TM2) based on fluorescence reduction. Free metal content of growth media was determined by Visual MINTEQ (version 3.1). After 24 h, relative fluorescence of microalgae in the three media decreased with increased metal concentration showing a concentration dependent graded toxicity response. All microalgae were more sensitive to the metals when grown in TM1, when compared, more sensitive to Cr⁶⁺ than Cd²⁺. Metal speciation indicated that TM1 and TM2 media have higher percentage of bioavailable Cd²⁺ than BBM, and chromium was present mainly as CrO₄^2- and HCrO₄^-. The results suggest that the TM1 medium is more suitable under short term exposure of microalgae to metals in environmental monitoring.]]> Tue 22 Feb 2022 15:12:27 AEDT ]]> https://ogma.newcastle.edu.au/vital/access/ /manager/Repository/uon:24839 Coelosphaerium sp., Synechococcus sp., Oscillatoria sp. and Chroococcus sp. to environmentally relevant concentrations of Cr⁶⁺, Cd²⁺ and Zn²⁺was assessed based on fluorescence change as a proxy for growth reduction. At 24 h exposure, the growth reduction inthe cyanobacteria followed the order: Zn²⁺ < Cr⁶⁺ ≤ Cd²⁺. Of the four cyanobacteria, Synechococcus was the most sensitive for Cr⁶⁺, where as Chroococcus was the most sensitive for Cd²⁺ and Zn²⁺. Sensitivity was gradually decreased by 96 h implying the acquisition of tolerance by cyanobacteria to heavy metal ions with prolonged exposure.]]> Sat 24 Mar 2018 07:11:19 AEDT ]]>