Authors: Mónica M Storni María Cristina Zaccaro Ana Capano Ana María Stella Gloria Zulpa
Publish Date: 2007/04/13
Volume: 23, Issue: 6, Pages: 833-836
Abstract
Metal ions are both essential and potentially toxic The aim of this work was to demonstrate that diazotrophic cyanobacterium Tolypothrix tenuis N° 54 can tolerate toxic concentrations of Ni2+ in order to use the biomass in biofilters or as biofertilizer For this purpose growth pigment and protein contents and catalase activity of T tenuis growing in increasing concentrations of Ni2+ ranging from 10−10 to 10−4 M were assesed The strain did not grow at Ni2+ concentration of 10−4 M but at lower concentrations there were no significant differences with the control it was tolerant at 10−10 and 10−8 M Nickel concentration of 10−6 M is toxic for this cyanobacterial strain because dry weight decreased by 30 allophycocyanin and phycoerythrin decreased by 92 and 98 respectively and protein content increased by 42 Chlorophyll a concentration was more than double the control value in 10−10 and 10−8 M but in 10−6 M it decreased by 19 Catalase EC 11116 activity doubled the control value in the lowest nickel concentration whereas in 10−8 M there was no significant difference with the control and in 10−6 it decreased by 78 The living biomass of this strain could be used as a step in the bioremediation process in waters contaminated with concentrations of nickel lower than 10−6 M and eventually as a biofertilizer
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