ISSN 2169-3048
International Journal of Biochemistry and Biotechnology ISSN: 2169-3048 Vol. 2 (1), pp. 343-252, January , 2013. © International Scholars Journals
Full Length Research Paper
Comet assay and some biochemical studies on Bacillus cereus using heavy metals and ultraviolet (UV)
D. E. El-Hadedy* and S. M. El-Sonbaty
Department of Microbiology, National Center for Radiation Research and Technology,
Egyptian Atomic Energy Authority, Cairo, Egypt.
*Corresponding author. E-mail: [email protected]
Received 06 October, 2012; Accepted 12 January, 2013
Abstract
Genotoxicity tests (comet assay) are used to detect the toxicity of the materials that causes damage to the deoxyribonucleic acid (DNA). Bacillus cereus strain used in this study was isolated and identified previously by 16S rRNA with accesion number AB599718.1. This study aimed to investigate the impact of ultraviolet (UV) and environmental pollutants (cadmium and lead) on B. cereus as a bacterial contaminant of food. B. cereus was grown on L.B medium supplement with lead or cadmium followed by exposure to UV radiation as combined effect with heavy metal. To study the cytogenetic shape of total DNA genomic in individual cells. DNA damage (genotoxicity) was analyzed by using comet assay. The results indicated that, the metabolic rate of B. cereus was affected by the metal adsorption rate. Changes in the concentration of DNA damage, glutathione (GSH) (record 13 mg/mg protein with 1 mM Cd, 13 mg/mg protein without Cd and lead and high value with lead at 10 mM) while lipid peroxidation values were (7 nM/mg protein with Cd and high value 5.5 nM/ mg with lead). This method could be used as a useful biomarker for the identification of the presence of environmental contamination. In the future, for heavy metals removal, immobilized on waste biomaterials (there are no sense in this phrase). Input of heavy metals imposes a selective pressure that may favor the growth and activity of resistant/tolerant microbes.
Key words: Bacillus cereus, comet assay, ultraviolet (UV), cadmium, lead, glutathione, lipid peroxidation.