Evaluation of the benzo[a]anthracene biodegradation by animal bioassays

Abstract

Background: Benzo[a]anthracene (BAA), also known as "tetraphene" belongs to the polycyclic aromatic hydrocarbons (PAHs) which are considered as an important class of environmental genotoxins. The present work focused on the evaluation of the efficiency of the biodegradation of the BAA by Bacillus amyloliquefaciens using animal bioassays, which include micronucleus (MN) and DNA fragmentation as end point of genotoxicity of the resulting metabolites from BAA biodegradation. Results: B. amyloliquefaciens was exposed to different doses of γ radiation (0.5, 1.0, 1.5, and 2.0 kGy) kGy. The colonies for the wild strain and its variants obtained after radiation were counted. The final counts for variant 3 (V3), variant 4 (V4), and variant 5 (V5) have been increased from its initial count by (0.3, 0.48, and 0.1 log cycle) respectively at 1 mg/ 100 ml (BAA). For animal bioassay, male mice were divided into seven groups; control group received vehicle only, groups II and III were injected with 5 and 10 mg/kg b.wt (BAA) respectively, and groups IV, V, VI, and VII were injected with the residues of BAA after biodegradation with wild type, V3, V4, and V5 of B. amyloliquefaciens respectively. Conclusions: Results of the micronucleus test and the DNA fragmentation as end point of genotoxicity of (BAA) indicated that B. amyloliquefaciens have the efficiency in biodegradation of (BAA) to nongenotoxic metabolites where (V3) and (V4) are more efficient than the wild type and (V5). So B. amyloliquefaciens could solve the problem of soil and water contamination by oil spill or industrial petroleum waste by ecofriendly manner.

Microalgae–Bacteria Consortia: A Review on the Degradation of Polycyclic Aromatic Hydrocarbons (PAHs)

“…In animal studies it has been found to be genotoxic, carcinogenic that induce skin, lungs, and liver tumors in the young mice after dermal application, absorption, subcutaneous and intraperitoneal injection. It was found to cause micronucleus and DNA fragmentation in mice [53].…”