Effects of critical levels of heavy metal on valuable compounds of Dunaliella salina

Effects of critical levels of heavy metal on valuable compounds of Dunaliella salina

Although some heavy metals provide essential trace elements, most of them can be toxic to all forms of life at high concentrations due to formation of complex compounds within the cell. Once these elements introduced to an environment they cannot be self-degraded but some species of micro-organisms have evolved several mechanisms to tolerate their presence. Microalgae are studied as beneficial micro-organisms for bio-remediation of polluted industrial wastes which have significant secondary products for pharmaceutical and sanitary industries, fishery food, biofuel production. In this study effects of high and critical values of cadmium chloride on Dunaliella salina were studied. Three levels of heavy metal (30, 60 and 90 mg/L CdCl2) were used as a source of stress and added acutely and in one step to 2 M NaCl basic media culture. Sampling was carried out in 13 days after treatment. Biomass, chlorophyll a and b, total carotenoids, beta-carotene and glycerol were extracted and measured to study the changes. Results show that all levels of CdCl2 had meaningful increases on all products after 24 ours. Biomass had maintained the steady growth rate in all levels. Based on the results D. salina could introduce as one of the most resistant species against cadmium chloride.

Although some heavy metals provide essential trace elements, most of them can be toxic to all forms of life at high concentrations due to formation of complex compounds within the cell. Once these elements introduced to an environment they cannot be self-degraded but some species of micro-organisms have evolved several mechanisms to tolerate their presence. Microalgae are studied as beneficial micro-organisms for bio-remediation of polluted industrial wastes which have significant secondary products for pharmaceutical and sanitary industries, fishery food, biofuel production. In this study effects of high and critical values of cadmium chloride on Dunaliella salina were studied. Three levels of heavy metal (30, 60 and 90 mg/L CdCl2) were used as a source of stress and added acutely and in one step to 2 M NaCl basic media culture. Sampling was carried out in 13 days after treatment. Biomass, chlorophyll a and b, total carotenoids, beta-carotene and glycerol were extracted and measured to study the changes. Results show that all levels of CdCl2 had meaningful increases on all products after 24 ours. Biomass had maintained the steady growth rate in all levels. Based on the results D. salina could introduce as one of the most resistant species against cadmium chloride.