Chemical-specific continuous biomonitoring using a recombinant bioluminescent bacterium DNT5 (nagR-nagAa: :luxCDABE)

The recombinant bioluminescent bacterium, DNT5, containing a nagR-nagAa::luxCDABE fusion, was tested in a multi-channel continuous monitoring system to evaluate its ability to detect benzoic acid derivatives. Seven chemicals, benzoic acid, salicylic acid, 2,5-dihydroxy benzoic acid, 3,5-dihydroxy benzoic acid, benzene, naphthalene and phenol, were used to characterize the responses of DNT5. This strain responded uniquely to each chemical, and these responses were then evaluated based upon the structures of each chemical. The greatest bioluminescent responses were to salicylic acid and benzoic acid, followed by 2,5-dihydroxy benzoic acid and 3,5-dihydroxy benzoic acid, but DNT5 was unresponsive when exposed to benzene, phenol and naphthalene, suggesting it has a strong preference for benzoic acid derivatives with few or no ring-substituted groups.