Toxic effects induced by salt stress on selected freshwater prokaryotic and eukaryotic microalgal species.
In order to determine the short-term impact induced by salt stress, cultures of Dictyosphaerium chlorelloides and Microcystis aeruginosa were grown in presence of increasing sea-salt concentrations. Growth rate and photosystem II activity in D. chlorelloides, and photosynthetic oxygen production (in both species) were analyzed. A concentration-dependent response was obtained with the presence of sea-salt in culture medium, being M. aeruginosa (EC(50(72)) = 76.6 mM) more sensitive to salt stress than D. chlorelloides (EC(50(72)) = 340.7 mM). However, comparative analysis between growth and Phi(PSII) inhibition in D. chlorelloides shown that there are not significant differences among EC(50(72)) values obtained. An immediate toxic response, induced by increase of sea-salt concentration, has been obtained applying the calculated EC(50(72)) values in both species. These results shown that sea-salt acts as a sensitive and rapid toxic compound in algal cells, and that the sensitivity of M. aeruginosa to salinity stress is much higher than that of D. chlorelloides.
Bartolomé
M C
MC
Facultad de Quimicofarmacología, Universidad Michoacana de San Nicolás de Hidalgo, Morelia, Mexico.
D'ors
A
A
Sánchez-Fortún
S
S
D000704:Analysis of Variance; D000460:Chlorophyta / Q000187:drug effects* / Q000254:growth & development*; D005618:Fresh Water; D046931:Microcystis / Q000187:drug effects*; D010100:Oxygen / Q000378:metabolism; D045332:Photosystem II Protein Complex / Q000378:metabolism*; D012965:Sodium Chloride / Q000633:toxicity*; D013045:Species Specificity
D045332:Photosystem II Protein Complex; D012965:Sodium Chloride; D010100:Oxygen