Combatting pesticide pollution: using liquid scintillation spectrometry to assess 14C-labeled hexachlorobenzene removal by mangrove Bacillus spp.

This study explored the ability of two Bacillus species isolated from mangrove sediments to degrade hexachlorobenzene (HCB), a persistent organic pollutant that affects the quality of surface water, groundwater, and soil. Hence, we analyzed bacterial growth in a medium with hexachlorobenzene as the sole carbon source. Moreover, chemical oxygen demand removal, ecotoxicity, and measured radiolabeled HCB degradation were assessed. Our results revealed that both Bacillus strains (I3 and I6) demonstrated hexachlorobenzene-degrading potential and achieved degradation rates of 11.5 ± 1.47% and 21.1 ± 0.84%. Additionally, the ability of these strains to mineralize HCB was confirmed by the production of radiolabeled carbon dioxide, assessed by liquid scintillation spectrometry and thin-layer chromatography. Ecotoxicity assays further demonstrated the effectiveness of bacteria treatment in degrading HCB. These findings underscore the potential of Bacillus strains from mangrove sediments to degrade and mineralize HCB, opening new perspectives for the bioremediation of aromatic compounds in contaminated environments.