| In order to study the effects of different yttrium（Y3+） concentrations on the physiology and microcysin-LR（MC-LR），the M．aeruginosa FACHB912 was used in this work. The effects of different Y3+ concentration on M.aeruginosa under 1.00 mg·L-1 Pb2+ stress were investigated. Based on the growth curve of M.aeruginosa, the activity of antioxidant enzymes including SOD, POD, CAT, and the content of malondiadehyde（MDA） and microcystic toxins（MC-LR）, results showed that obvious auxo-actions to the growth of M.aeruginosa, could be observed at relatively low concentrations of Y3+（0.10~0.50 mg·L-1） with Pb stress. Correspondingly, the activities of SOD, POD, and CAT in M．aeruginosa were enhanced, and the MDA presented decrease significantly. When the higher concentrations（1.00~10.00 mg·L-1） of Y3+ was employed, more severely inhibition to the growth of M.aeruginosa could be observed. When the concentrations were in the range of 0.50~10.00 mg·L-1, the content of MDA and MC-LR increased immediately and the activity of antioxidant enzymes was reduced, which potentially lead to the decline of the ability of eliminating the reactive oxygen species. Moreover, the antioxidant defense system was destroyed, and the growth of M.aeruginosa was seriously inhibited correspondingly. The typical "Hormesis" effects can be observed as the yttrium was employed on M.aeruginosa. |
