Influence Of The Physical And Chemical Factors On The Physiology Of Dunaliella. Salina

In many environmental factors of the marine pollution, the increase of UV-B (280nm～320nm) radiation because of the ozone layer weakened and the accumulation of some toxic meterials such as the heavy metals are highly concerned. The algae are one of primary producers. In the ecosystem, they are the fundermental for the material and energy circulations. The marine environment pollution will directly affect the growth and the metabolism of the algae, and then influence the entire ecosystem.D. Salina is a valuable halotolerant unicellular green alga. It mainly distribute in some salt lakes and oceans. It is the most halotolerant alga in the world. D. Salina is well known due to its ability to produce large quantities ofβ-carotene under defined stress conditions. This article studied the effects of UV-B radiation, and different density Pb²⁺, Cd²⁺, Co²⁺ on D. salina. The results as follows:1.UV-B radiation has the significant influence to the sphysiological process of D. salinla.Under given UV-B radiation doses in this experiment, the soluble protein synthesis was suppressed. The stronger of radiation intensity gave to the algae, the more obvious of the suppression. The total chlorophyll content obviously reduced with the increase of the radiation. The MDA content increased with the increase of radiation dose. The soluble sugar synthesis was suppressed and the algae's cell membrane was injured and also SOD activities elevated under higher concentrations of the metals that indicated that in the algae cells the active oxygen species were at the flourish condition.2.Pb²⁺,Cd²⁺,Co²⁺have the obvious influence to the physiological processes of Dunaliella SalinaUnder different densities of three heavy metals Pb²⁺,Cd²⁺,Co²⁺ , the chlorophyll content of D . Salina reduced with the increases of the concentrations; under lower concentrations, the soluble protein content slightly increased. However, the synthesis of soluble protein was suppressed under higher concentration of three heavy metals. The influences of three heavy metals to the soluble sugar content were minor. The treated algae all produced many ASA and the POD, which showed the alga had a very active antioxidase system to protect itself. The order of toxicity of three heavy metals was Cd²⁺ > Pb²⁺> Co²⁺.