Study On Bioconcentrating Ability And Mechanism Of Gelidium Amansii, Corallina Officinalis, Enteromorpha Linza And Sargassum Confusum On Heavy Metals In Seawater

Four kinds of macroalgae(Gelidium amansii, Corallina officinalis，Enteromorpha Linza and Sargassum confusum) under heavy metals (Cu, Pb, Cd, Crand Zn) mixing condition, their adsorption capacity and tolerance ability. The purposeis to screen out one or more kinds of macroalgae which have strong enrichmentcapacity and tolerance to the heavy metals, and have broad application prospectof bioremediation, and to provide scientific basis for the bioremediation of heavymetals pollution of coastal waters. The main results are as follows:(1) After cultivated in seawater containing five kinds of heavy metals(Cu, Pb, Cd, Cr and Zn) for15days, the accumulations of heavy metals in four kindsof macroalgae(Gelidium amansii, Corallina officinalis, EnteromorphaLinza and Sargassum confusum) were different: The largest accumulation of Cd up to4.63mg/kg in Corallina officinalis; that of Zn up to899.93mg/kg in EnteromorphaLinza; and that of Cu, Pb and Cr up to49.03mg/kg,51.79mg/kg and30.15mg/kg inSargassum confusum, respectively. According to the different heavy metalscontamination in seawater to choose suitable macroalgae for bioremediation.(2) With the concentration of heavy metals in seawater increasing, exceptEnteromorpha Linza, the relative growth rat（eRGR）of other macroalgae decreased indifferent degree；the contents of chlorophyll a in Corallina officinalis, EnteromorphaLinza and Sargassum confusum changed not obviously, but the contents in Gelidiumamansii showed a downward trend; Net photosynthetic rate of four kinds ofmacroalgae showed a downward trend, also; Respiration rate have different changetrends of four kinds of macroalgae, the rate of Corallina officinalis changed notsignificantly, the rate of Gelidium amansii increased at first and then decreased, the rate of Enteromorpha Linza and Sargassum confusum showed a downwardtrend; With the concentration of heavy metals in seawater increasing, the permeabilityof cell membrane of Gelidium amansii, Corallina officinalis, EnteromorphaLinza and high concentration groups of Sargassum confusum increased gradually.According to the macroalgae tolerance to the different concentration of heavy metals,choosing macroalgae which have good relatively growth and strong enrichmentcapacity to repair heavy metals contamination in seawater.(3) After EDTA treatmented, we can know that a considerable part of heavymetals by Gelidium amansii absorbed have located in the cell wall space, maximumratio were: Cu45.9%, Pb79.2%, Cd46.8%, Cr37.2%, Zn90.2%; that ratio of Corallinaofficinalis were: Cu44.6%, Pb75.6%, Cd44.0%, Cr28.3%; that ratio of EnteromorphaLinza were: Cu70.4%, Pb90.6%, Cd48.2%, Cr66.9%, Zn89.9%; that ratio of highconcentration groups of Sargassum confusum were: Pb39.9%, Cd33.1%, Cr25.1%andZn66.5%. The metal ions which into the protoplasts induced synthesis ofmetallothionein (MT), with the concentration of heavy metals in seawater increasing,the contents of MT in four kinds of macroalgae showed a rising trend.