POTENTIALITY OF CHROOCOCCUS MINUTES (CYANOPHYTA)

AND CHLORELLA VULGARIS (CHLOROPHYTA) ISOLATED FROM MANZALA LAKE FOR BIOREMEDIATION

OF CADMIUM AND LEAD

Ibrahiem M. Shaker1*;
Islam M. El-Manawy2;

Mona H. Ahmed1 and Mohamed M. Salama1

1Limnology dept, Central Lab. for Aquaculture Research, Agricultural Research Center, Egypt.

2Botany Department, Faculty of Science, Suez Canal University, Egypt.

* Correspondent author: email: [email protected]

Received 14/ 11/ 2019

Accepted 15/ 12/ 2019

Abstract

There are multiple benefits and uses of micro-algae of different species especially their role in the bioremediation of heavy metals. This study which be occurred in phyto-lab. of Limnology Department, Central Laboratory for Aquaculture Research (CLAR), Abbassa, Abou-Hammad, Sharkia, Egypt, aimed to explain the role of two wild algal species; Chlorella vulgaris as green alga and Chroococcus minutus as Cyanobacteria isolating from El-Ginka location in Manzala lake for bioremediation of heavy metals Cd+2 and Pb+2 from aqueous solutions through exposing of both algae to different concentrations of Cd+2 and Pb+2. Optical density and chlorophyll “a” as indicators of growth rate were measured every three days in all concentrations. In case of Chroococcus; it was noticed that the removal percentage of Cd reaches to 54.43 and 48.05% in the two higher concentrations 0.4 and 1.0 ppm, which exposed to the alga till the last day from the experiment. While removal percentage of lead (51.44 and 38.98%) was recorded in the 12th day of the experiment for 10 and 20 ppm and decrease to 30.98 and 29.43% for two concentration; 30 and 40 ppm, respectively. The reduction in the amount of Cd+2 by Chlorella after 12 days of culturing was 53.26%, 78.33%, 85.87% and 87.95% for 2.0, 4.0, 6.0 and 8.0 ppm; respectively. Chlorella could also remove Pb+2 48.23%, 67.08%, 72.94 and 84.98 for 3, 6, 12 and 18ppm, respectively after 12 days from the medium. This means that the heavy metal uptake ability of Chlorella can be exploited for metal detoxification and environmental clean-up operations. This study provides a deep insight for exploring potential of using algal species isolated from polluted sites for bioremediation of heavy metals.

Keywords: Bioremediation, heavy metals, green alga, Cyanobacteria, Chlorella, Chroococcus.