EFFECTS OF PH ON TOXICITY OF CADMIUM, COBALT AND COPPER TO THE GREEN ALGA SCENEDESMUS BIJUGA

Document Type : Original Article

Author

Botany department, Faculty of Science, El-Minia University, El-Minia, Egypt.

Abstract

This study was conducted to elucidate the effects of pH on the toxicity of cadmium, cobalt and copper to the green alga Scenedesmus bijuga. The sublethal concentrations of Cd2+, Co2+ and Cu2+ were obtained at 10-6, 10-5, 10-5 M, respectively. A standard initial inoculum of the tested alga was used to inoculate the culture flasks containing Kuhl's medium with different pH values (4, 6, 8, 10 and 12) supplied with the sublethal concentrations of each tested metal.  The results revealed that the growth of Scenedesmus bijuga increased with increasing pH. However, the accumulation, the accumulation factor and the amount of free ionic forms of each metal decreased.  Generally, it appears that the tested metals exert more toxic effect in acidic than in alkaline pH conditions.

Keywords


Anderson, M. A. and Morel, F. M. M. (1982). The influence of aqueous iron chemistry on the uptake of iron by the coastal diatom Thalassiosira weissflogii. Limnol. Oceanogr., 27:789-813
Baudo, R. (1987). Heavy metal pollution and ecosystem recovery. Ecological assessment of Environmental Degradation, Pollution and Recovery, Lectures of a course held at the Joint Research Center, Ispra, ITALY, O. Ravera (Ed.), pp.325-352.
Brooks, R. R. and  Rumsby,  M. G. (1965). The biogeochemistry of trace element uptake by some New Zealand bivalves.  Limnol. Oceanogr., 10: 521-566.
Campbell, P. G. C. and Stokes, P. M. (1985). Acidification and toxicity of metals to aquatic biota. Can. J. Fish. Aquat. Sci., 42: 2034 –2050.
De Filippis, L.F.; Hampp, R. and Ziegler, H. (1981). The effects of sublethal concentrations of zinc, cadmium and mercury on Euglena :1- growth and pigments.  Z. Pflanzenphysiol., 101: 37-47.
Fathi, A. A. (1995). Physiological and biochemical studies on some Nile water phytoplankton as influenced by some heavy metals and their interaction with environmental factors. Ph.D. Thesis, El-Minia University, El-Minia, Egypt. 125p.
Fathi, A. A. (2002). Toxicological response of the green alga Scenedesmus bijuga to mercury and lead.  Folia Microbiol., 47: 667-671.
Fathi, A. A. and Falkner, G. (1997). Adaptation to elevation of the concentration of the trace element copper during growth of Scenedesmus bijuga is reflected in the properties of the copper uptake system. T. Micropr. Techniqu., 15: 321 – 333.
Fathi, A. A. and Zaki, F. T. (2003). Role of proline level in ameliorating heavy metal toxicity in Scenedesmus bijuga. El-Minia Sci. Bull., 14: 155 – 167.
Fathi, A. A.; Zaki, F. T. and Fathy, A. A. (2000).  Bioaccumulation of some heavy metals and their influence on the metabolism of Scenedesmus bijuga and Anabaena spiroides. Egypt J. Biotechnol., 7: 293-307. 
Gadd, G. M. (1988). Accumulation of metals by microorganisms and algae. In: Rehm HJ (ed) biotechnology, vol 66. VCH, Weinheim, pp. 401-433.
Hofner, W.; Naguib,  M. I.; Kobbia, I. A.; and Kahlil,  Z. (1987). Use of laboratory cultures of some algae to predict heavy metal toxicity. Egypt. .J. Microbiol., 22: 213-226
Janssen, C. R.; Heijerick, D. G.; De schamphelaer, K.A. and Allen, H. E. (2003). Environmental risk assessment of metals: tools for incorporating bioavailability. Environ. Int.,  28: 793-800.
Khalil, Z. (1997). Toxicological response of a cyanobacterium, Phormidium fragile, to mercury. Water, Air, and Soil pollution, 98:179-185.
Kuhl, A. (1962). Zur physiologie der Speicherung Kondensierter organisher phospahte in Chlorella. Vortag Bot. Hrsg. Deut. Botan. Ges. (N.C.)., 1: 157-166.
Langston, W. J. (1990). Toxic effects of metal and the incidence of metal pollution in marine ecosystem. In R.W. Furness & P.S. Rainbow (eds.), Heavy metals in the marine Environment (pp. 101-1022). Boca Raton, FL: CRC Press.
Lobban, C. S. and Harrison, P. J. (1997).  Seaweed Ecology and Physiology. Cambridge University. pp 366.
Lorch, D. and Weber, A. (1985). Accumulation, toxicity and localization of lead in cryptograms: experimental results. Symp. Biol. Hungar., 29: 51- 82.
Metzner, H.; Rau, H. and Senger, H. (1965).  Untersuchungen zur synchronisierbar karkeit einzellner-  Pigment. Mangel Mutanten von  chlorellaPlant., 65: 186-194.
Michnowiez, C. J. and Weaks, T. E. (1984). Effect of pH toxicity on As, Cr, Cu, Ni and Zn to Selenastrum capricornutum Printz. Hydrobiologia, 118: 299-305.
Müller,  K. W. and  Payer,  H.D. (1979).  The influence of pH on the cadmium-repressed growth of the alga Coelastrum proboscideum. Physiol. Plant., 45:415-433.
Nakajima, A.; Horikoshi, T. and  Sakaguchi,  T. (1981). Studies on the accumulation of heavy metal elements in biological systems XVII. Selective accumulation of heavy metals ions by Chlorella vulgaris. Eur. J. Appl. Microbiol.  Biotechnol., 12: 76-83.
Okamoto, O. K.; Pinto, E.; Latorre, L. R.; Bechara, E. J. and  Colepicolo, P. (2001). Antioxidant modulation in response to metal-induced oxidative stress in algal chloroplasts. Arch. Environ. Contam. Toxicol., 40: 18-24.
Pawlik, S. B. (2001).  Phtytochelatin production in freshwater algae Stigeoclonium in response to heavy metals contained in mining water; effects of some environmental factors. Aquat. Toxicol., 52: 241-249.
Peterson, H. G.; Healey, F. P. and Wagemann, R. (1984). Metal toxicity to algae: a highly pH dependent phenomenon. Can. J. Fish. Aqat. Sci., 41: 974 –979.
Pollumaa, L.; Maloveryan, A.; Trapido, M.; Sillak, H. and Kahru, A. (2001). Study of the environmental hazard caused by the oil shale industry solid wastes. Altern Lab Anim., 29: 259-267.
Rai, L. C. and Dey, R. (1980). Environmental effects on the toxicity of methylmercuric chloride to Chlorella vulgaris.  Acta  Hydrochi. Hydrobiol., 8: 319-325
Rai, L.C.; Gaur, J. P. and Kumar, H. D. (1981). Phycology and heavy-metal pollution. Biol. Rev., 56: 99-112
Rai L.C., Mallick N., Singh  J.B. and Kumar, H.D. (1991). Physiological and biochemical characteristics of a copper tolerant and a wild type strains of Anabaena doliolum  under copper stress. J. plant physiol. 138, 68-74
Reed, R. H. and Gadd, G. M. (1990).  Metal tolerance in eukaryotic and prokaryotic algae. In: Shaw J(ed) Heavy metal tolerance in plants: evolutionary aspects. CRC, press, Boca Raton, Fla. 105-118.
Siripornadulsil, S.; Traina, S.; Verma, D. P. and Sayre, R.T. (2002). Molecular mechanism of proline-mediated tolerance to toxic heavy metals in transgenic microalgae. Plant Cell, 14: 2837-2847.
Sponza, D. T. (2002).  Necessity of toxicity assessment in Turkish industrial discharges (examples, heavy metals and textile industry effluents. Environ. Monit. Assess., 73: 41-66
Stokes, P. M. (1983). Response of fresh water algae to metals. In:  Round FE, chapman DJ(eds), progress in phycological research, 2. Elsevier, N.Y., 87-112.
Stumm, W. and Morgan, J. J. (1981). Aquatic Chemistry, 2 ed., Wiely, New York, pp780.
Vymazal, J. (1990). Uptake of heavy metals by Cladophora glomerata. Acta Hydrochim. Hydrbiol., 18: 657-665.
Vymazal,  J. (1995). Algae and element cycling in wetlands. Lewis publishers, Boca Raton, pp 689.
Winch, S.; Ridal, J. and    Lkean, D. (2002).  Increased metal bioavailability following alteration of freshwater dissolved carbon by ultraviolet exposure. Environ. Toxicol., 17: 267-274.