Effects of various elements on arsenic accumulation of the alga Dunaliella salina

Abstract

The effect of 23 various elements (nitrogen, manganese, magnesium, molybdenum, zinc, selenium, gallium, nickel, cobalt, lithium, strontium, vanadium, tin, antimony, bismuth, cadmium, chromium, lead, iron, silver, copper, potassium and calcium) in water on growth and arsenic accumulation in Dunaliella saline was investigated. The order of growth inhibition of D. salina by these elements was Ag > Cd > Co > Ni > Cu > Zn > Fe > Sb > Ga > C r > Bi> Sr > Mn > Sn >Se > Pb> V > Ca, Mg, Mo, K, Li.Arsenic accumulation in D. salina was unaffected by an increase in calcium and chromium. Also, the arsenic content in D. salina decreased at a potassium concentration of 100 mg dm-j, and was also reduced by the addition of cadmium and nitrogen; however, it was increased by the addition of lithium at 100 mg dm-', tin, gallium, bismuth, strontium, vanadium, iron and manganese at 10 mg mdA3, lead, antimony, zinc, copper cobalt and nickel at 1 mgdm-', selenium at 0.1 mg dm-j, and silver at 0.005 mg dm-', respectively. These results imply that arsenic accumulation by D. salina depends upon biological activity and physical adsorption. Keywords: Arsenic, Dunaliella salina, microalgae, elements, accumulation lNTRODUCTlON The use of marine organisms for the removal of toxic and valuable elements from wastewater has continued to attract considerable attention in recent years, particularly because they are available at little or no cost and are capable of accumulating the elements by incorporation, adsorption, chelation and ion exchange.' The microalgae (Chlorella ,' D~naliella,~ Phoridinium ') are capable of accumulating arsenic to concentrations several orders of magnitude higher than in the surrounding medium. In fact, microalgae can be employed for the purification of arseniccontaminated water. In recent work we have shown that D. salina accumulated arsenic at rates as high as those of other algae.5 This high accumulation capacity can even be used for the enrichment or recycling of arsenic. Because this observation could have a significant impact on arsenic recovery, we have initiated a thorough investigation of arsenic accumulation by D. salina. No information has been reported on the effects of various elements on arsenic accumulation by D. salina. There is also little information on the accumulation of arsenic by Dunaliella sp. ( D . sp) over eight hours under conditions of co-existence with arsenic, and phosphorus, chlorine, molybdenum, managanese, copper and cadmium.6 This report describes the effects of various elements (nitrogen, manganese, magnesium, molybdenum, zinc, selenium, gallium, nickel, cobalt, lithium, strontium, vanadium, tin, antimony, bismuth, cadmium, chromium, lead, iron, silver, copper, potassium and calcium) on arsenic accumulation and growth inhibition of D . salina in coexistence with arsenic and various elements. MATERIAL AND METHODS MicroalgaeD. salina 19/30 (Chlorophyceae) was obtained from the Culture Collection of Algae and Protozoa (University of Cambridge, UK) and was used throughout the experiments. ...

The Effects of Operational Parameters on the Iron(III) Uptake by Micro‐Algae Dunaliella salina

“…As well as other strains of micro‐algae, D. salina has long been of scientific interest for its ability to bind heavy metals in aqueous solutions and its bioremediation capability. Several investigations have been reported on cadmium, arsenic, lead, mercury, and aluminium uptake by Dunaliella algae . It should be noted that D. salina has a higher affinity for some heavy metal ions.…”

“…Several investigations have been reported on cadmium, arsenic, lead, mercury, and aluminium uptake by Dunaliella algae. [15][16][17][18][19] It should be noted that D. salina has a higher affinity for some heavy metal ions. It was shown that, under the same conditions, D. salina cells present high tendency for zinc accumulation, followed by copper and cobalt, the lowest tendency is for cadmium.…”

Selenium Accumulation in Unicellular Green Alga Chlorella vulgaris and Its Effects on Antioxidant Enzymes and Content of Photosynthetic Pigments

“…To date, investigations on this subject have centered on the production of Se-enriched biomass as a health food or animal feed supplement [35] , [36] and on the use of marine plants for the removal of toxic elements, including Se [37] . Interestingly, nutrient interactions between Se and other minerals can affect their retention.…”

Cellular response of Chlorella zofingiensis to exogenous selenium

“…In aquatic ecosystems, the concentration of trace elements influences the species composition of the associated algal community (Moede et al 1980). To date, investigations on this subject have centered on the production of selenium-enriched biomass as a health food or animal feed supplement (Pronina et al 2002;Li et al 2003) and on the use of marine organisms for the removal of toxic elements, including selenium (Yamaoka et al 1994). However, only very few studies have focused on the cellular response of algae to selenium stress, among them studies that were aimed solely at seeking heat-shock proteins as biomarkers (Bierkens et al 1998).…”