Abstract
Ethidium Bromide (EtBr) is an organic compound used in molecular biology investigations. EtBr ability of intercalating in the DNA molecule makes it a toxic substance. The objective was to evaluate the phycoremediation potentials of Chlorella vulgaris, Desmodesmus subspicatus and Raphidocelis subcapitata tested separately and in a mixture (Mix) for EtBr removal from the aqueous medium. Experiments were conducted using an initial algae biomass of 106 cell/mL, exposed to 500 µg/L of EtBr. The removal efficiency (µg EtBr L−1) after 3 h in each treatment were: Mix (72.8 µg.L−1) >D. subspicatus (48.4 µg.L−1) >R. subcapitata (24.6 µg.L−1) >C. vulgaris (19.9 µg.L−1). However, when EtBr mass reduction per microalgae density is considered (ng.algae−1), the efficiency ranking changes to: D. subspicatus (1.9 × 10−5 ng.algae−1) >C. vulgaris (1.4 × 10−5 ng.algae−1) >Mix (9.8 × 10−6 ng.algae−1) >R. subcapitata (2.8 × 10−6 ng.algae−1). The results suggest that initial algal population density is a determinant factor for efficient EtBr removal by microalgae species in short term treatments. In order to obtain 100% of EtBr removal, it should be necessary 1010, 1010 and 1011 algae.mL−1 of C. vulgaris, D. subspicatus and R. subcapitata, respectively. The results strongly suggest phycoremediation can be explored as an alternative method for EtBr removal.
Acknowledgment
Rodrigo Coutinho and Priscila Cunha from laboratory LABIFI at Rio de Janeiro State University-UERJ, Kissila Rabelo and Mario José dos Santos Pereira from the Laboratory of Electron Microscopy and Confocal-UERJ, Brazil are also acknowledged for their technical assistance.
Disclosure statement
No potential conflict of interest was reported by the author(s).